This is a classic 'Political Theory' question, moving beyond Article memorization to conceptual clarity. It tests if you can distinguish between a specific *type* of constitution (Federal/Parliamentary) and the *definition* of Constitutionalism itself. The answer lies in the first chapter of NCERT Class XI.
How this question is built
This question can be broken into the following sub-statements.
Tap a statement sentence to jump into its detailed analysis.
Statement 1
Does "constitutional government" mean a representative government of a nation with a federal structure?
Origin: Weak / unclear
Fairness: Borderline / guessy
Indirect textbook clues
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 92: World Constitutions > 2021 TEST PAPER > p. 762
Strength: 5/5
“UPSC Questions on Indian Polity (General Studies-Prelims 2013-2023)
(c) A Sovereign Secular Democratic Republic
(d) A Sovereign Socialist Secular Democratic Republic
17. Constitutional government means
(a) a representative government of a nation with federal structure
(c) a government whose Head enjoys real powers
(d) a government limited by the terms of the Constitution
18. Consider the following statements in respect of Bharat Ratna and Padma Awards:
Which of the above statements are not correct?
• (a) 1 and 2 only • (b) 2 and 3 only • (c) 1 and 3 only • (d) 1, 2 and 3”
Why relevant
This UPSC question lists as options both 'a representative government of a nation with federal structure' and 'a government limited by the terms of the Constitution', implying 'constitutional government' is contrasted with those meanings.
How to extend
A student could use this contrast to test which option fits standard usage by checking other sources/examples where 'constitutional government' is equated with limitation by law rather than necessarily federal/representative form.
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 14: Federal System > Federal System > p. 137
Strength: 4/5
“Single government, that is, the national government which may create regional governments • Federal Government: 2. Written Constitution; Unitary Government: 2. Constitution may be written (France) or unwritten (Britain) • Federal Government: 3. Division of powers between the national and regional government; Unitary Government: 3. No division of powers”
Why relevant
Defines key features of a federal government (written constitution, division of powers) showing 'federal' is a distinct technical category.
How to extend
Use this rule to judge that 'federal structure' is a separate property from being 'constitutional' and so cannot be assumed to be implied by 'constitutional government'.
Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 16: India–Political Aspects > Federal States > p. 2
Strength: 4/5
“This is what permits diverse peoples and even cultures to join a single state. Their first allegiance may be to their own region, but their ultimate loyalty is towards the state. A federal government has a written constitution that cannot be unilaterally altered. There is division of power between the central government and the component states/provinces. The federal government is generally formed in the countries where the people belong to different racial, ethnic, cultural groups; speak different languages; follow different religions; and have different customs and traditions. In a federal set-up, local governments derive their authority from the regional governments, which themselves possess constitutionally guaranteed autonomy in specified matters of importance.”
Why relevant
States a federal government has a written constitution that cannot be unilaterally altered, linking 'federal' to constitutional entrenchment but not equating 'constitutional government' with 'federal'.
How to extend
A student could compare examples of constitutional governments that are unitary (UK/France) to test whether 'constitutional' always implies federal structure.
Laxmikanth, M. Indian Polity. 7th ed., McGraw Hill. > Chapter 3: Concept of the Constitution > D I Federal and Unitary > p. 24
Strength: 4/5
“Based on the nature of relationship between the national government and the regional governments, the constitutions are classified into federal and unitary constitutions. A federal constitution is one which provides for a division of power between the national government and the regional governments. It enables them to operate in their respective jurisdictions independently. Federal constitution is prevalent in the USA, Switzerland, Australia, Canada, Russia, Brazil, and some other states. Unitary constitution is prevalent in the UK, France, Japan, China, Italy, Norway, and other states. The Constitution of India contains both the federal provisions as well as the unitary provisions. Hence, it was described as quasi-federal by K.C.”
Why relevant
Explains classification into federal and unitary constitutions and gives country examples, reinforcing that 'constitutional' systems vary (federal vs unitary).
How to extend
A student can map the examples (e.g., UK is constitutional but unitary) to infer that 'constitutional government' does not necessarily mean 'federal'.
Introduction to the Constitution of India, D. D. Basu (26th ed.). > Chapter 13: The State Executive > 1. The General Structure > p. 269
Strength: 3/5
“. 1. The General Structure As stated at the outset, our Constitution provides for a federal Government, having separate systems of administration for the Union and its Units, namely, the States. The Constitution contains provisions for the governance of both. It lays down a uniform structure for the State Government, in Part VI of the . Constitution, which is applicable to all the States including the erstwhile State of Jammu & Kashmir. [Refer to chapter 15 for details] .”
Why relevant
Says 'our Constitution provides for a federal Government', indicating that 'constitution' can provide for federalism but that 'constitutional' describes the source/instrument rather than guaranteeing any specific form (representative/federal).
How to extend
A student could contrast constitutions that create different forms (federal/unitary, representative/monarchical) to judge whether 'constitutional government' implies the particular combination in the statement.
Statement 2
Does "constitutional government" mean a government whose head of state enjoys only nominal powers?
Origin: Web / Current Affairs
Fairness: CA heavy
Web-answerable
"While the Prime Minister is the head of the government, the President is the head of the State. In our political system the head of the State exercises only nominal powers. The President of India is like the Queen of Britain whose functions are to a large extent ceremonial."
Why this source?
- Directly states that in the described political system the head of state 'exercises only nominal powers.'
- Compares the President to the Queen of Britain as 'ceremonial,' linking constitutional office to nominal functions.
"In parliamen-tary systems, the head of government is a prime minister selected from the parliament, and is typically the leader of the majority political party or coalition. ... A separate head of state may be a monarch or an elected President (or comparable of-fi cial)."
Why this source?
- Explains parliamentary systems where the head of government is a prime minister selected from parliament.
- Notes that a separate head of state may be a monarch or an elected President — implying a distinct (and often ceremonial) head-of-state role in such constitutional systems.
"Head of state: the method of selection, powers, terms of office."
Why this source?
- States that constitutions specify the 'Head of state: the method of selection, powers, terms of office.'
- Indicates constitutional government defines the head of state's powers explicitly — suggesting those powers can vary and are not inherently only nominal.
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 3: Concept of the Constitution > II Definition > p. 25
Strength: 5/5
“It means government according to rule as opposed to arbitrary government; it means government limited by the terms of a constitution, not government limited only by the desires and capacities of those who exercise power." 14. ¥bema: A form of government can only be classified as constitutional when the rulers are subject to a body of rules and principles, which limit the exercise of their power.”
Why relevant
Gives a general definition: 'constitutional' means government limited by a body of rules/principles (rulers subject to constitution).
How to extend
A student can combine this with knowledge of systems (parliamentary vs presidential) to see whether limitation implies a nominal head.
Exploring Society:India and Beyond ,Social Science-Class VII . NCERT(Revised ed 2025) > Chapter 9: From the Rulers to the Ruled: Types of Governments > b. Constitutional monarchy > p. 201
Strength: 5/5
“Let us consider an example of a different kind of monarchy. The United Kingdom or Britain is also a monarchy. The head of the state is the king or queen, but he or she has only nominal power and the real power of the executive is exercised by the prime minister. The legislative power is exercised by the parliament. This means that all the laws are made by the elected parliament, and executive power is exercised by the Council of Ministers led by the prime minister. So while Britain has a king, it really is, today, a parliamentary democracy. This kind of monarchy is called a constitutional monarchy.”
Why relevant
Describes a constitutional monarchy (UK) where the monarch 'has only nominal power' and real executive power lies with the prime minister.
How to extend
Use this example to infer that in some constitutional systems the head of state is nominal, then check other constitutions for similar arrangements.
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 92: World Constitutions > JAPANESE CONSTITUTION > p. 684
Strength: 4/5
“All powers are vested in the single supreme Central Government located at Tokyo. The provinces derive their authority from the Central Government. The Diet can expand or diminish the authority and jurisdiction of the provinces. Thus, the provinces are subordinate units of government and enjoy only those powers which are delegated to them by the supreme Central Government. 4. Parliamentary Government Japan has shown a preference for the British Parliamentary System rather than the American Presidential System of Government. The features of the Japanese Parliamentary system of government are as follows: (i) The Emperor is the nominal executive while the Cabinet is the real executive.”
Why relevant
States for Japan (a parliamentary system) that 'The Emperor is the nominal executive while the Cabinet is the real executive.'
How to extend
Compare Japan with other constitutions: if a constitution establishes parliamentary government, the head of state is often nominal.
Democratic Politics-I. Political Science-Class IX . NCERT(Revised ed 2025) > Chapter 4: WORKING OF INSTITUTIONS > The President > p. 67
Strength: 4/5
“While the Prime Minister is the head of the government, the President is the head of the State. In our political system the head of the State exercises only nominal powers. The President of India is like the Queen of Britain whose functions are to a large extent ceremonial. The President supervises the overall functioning of all the political institutions in the country so that they operate in harmony to achieve the objectives of the State. The President is not elected directly by the people. The elected Members of Parliament (MPs) and the elected Members of the Legislative Assemblies (MLAs) elect her.”
Why relevant
Explains in the Indian context that the President is head of state with 'only nominal powers' while the Prime Minister is head of government.
How to extend
A student can test whether countries with written constitutions and parliamentary systems routinely make the head of state ceremonial.
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 31: Chief Minister > Chief Minister > p. 325
Strength: 3/5
“In the scheme of parliamentary system of government provided by the Constitution, the governor is the nominal executive authority (de jure executive) and the Chief Minister is the real executive authority (de facto executive). In other words, the governor is the head of the state while the Chief Minister is the head of the government. Thus the position of the Chief Minister at the state level is analogous to the position of prime minister at the Centre.”
Why relevant
Notes that in India's parliamentary system the governor is 'the nominal executive' while the Chief Minister is the real executive.
How to extend
Use this pattern (nominal head vs real executive) at subnational level to generalize that constitutional limits can produce ceremonial heads.
Statement 3
Does "constitutional government" mean a government whose head of state enjoys real (substantial) powers?
Origin: Web / Current Affairs
Fairness: CA heavy
Web-answerable
"While the Prime Minister is the head of the government, the President is the head of the State. In our political system the head of the State exercises only nominal powers. The President of India is like the Queen of Britain whose functions are to a large extent ceremonial."
Why this source?
- Explicitly states that in one constitutional system (India) the head of state exercises only nominal (ceremonial) powers.
- Shows that a constitutional government can have a head of state with largely ceremonial role, not substantial powers.
"In the United States, the President is both head of government and head of state. The President is elected separately from the legislature... In parliamentary systems, the head of government is a prime minister selected from the parliament... A separate head of state may be a monarch or an elected President (or comparable official)."
Why this source?
- Contrasts systems where the President is both head of government and head of state (United States) with parliamentary systems that separate the roles.
- Shows constitutional variation: some constitutions concentrate executive power in the head of state, others assign that power to a separate head of government.
"Head of state: the method of selection, powers, terms of office."
Why this source?
- Notes that constitutions specify the head of state's method of selection and powers, implying those powers vary by constitution.
- Supports the idea that 'constitutional government' does not fix a single level of power for the head of state—constitutions determine it.
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 3: Concept of the Constitution > II I Meaning > p. 25
Strength: 5/5
“The concepts of constitution and constitutionalism are closely related to each other. But, there are a few differences between them; like: • 1. A country may have the 'constitution' but not necessarily 'constitutionalism', For example, a country with a dictatorship, where the dictator's word is law, can be said to have a 'constitution' but not 'constitutionalism'. • 2. Constitutionalism recognises the need for government with power but, at the same time, insists that limitations should be placed on those powers. Unlimited power may lead to an authoritarian, oppressive government which jeopardises the freedom of the people. a "civilized" government. The real justification of the constitution finds place in having a "limited government" and of requiring those who govern to conform to laws and rules.”
Why relevant
Defines constitutionalism as insisting that limitations be placed on government powers and describes the purpose of a constitution as creating a 'limited government'.
How to extend
A student could use this rule to infer that 'constitutional government' emphasizes constrained powers (so head of state having large personal powers would conflict with this idea) and then check examples of constitutions to see whether heads of state are constrained.
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 3: Concept of the Constitution > MEANING > p. 22
Strength: 5/5
“Political scientists and constitutional experts have defined the constitution in the following way: Gilchrist: "The constitution consists of that body of rules or laws which determine the organization of government, the distribution of powers to the various organs of government, and the general principles on which these powers are to be exercised.,,1" Gettel1: "The fundamental principles that determine the form of a state are called its constitution. These include the method of which the state is organised, the distribution of its sovereign powers among the various organs of government, the scope and manner of exercise of governmental functions, and the relation of the government to the people over whom its authority is exercised".”
Why relevant
Gives definitions of constitution as the rules that determine organization of government, distribution of powers, and scope of exercise of functions.
How to extend
One can apply this pattern to test whether a country's constitution assigns substantial executive powers to the head of state (supporting the statement) or assigns them elsewhere (contradicting it).
Exploring Society:India and Beyond ,Social Science-Class VII . NCERT(Revised ed 2025) > Chapter 9: From the Rulers to the Ruled: Types of Governments > b. Constitutional monarchy > p. 201
Strength: 4/5
“Let us consider an example of a different kind of monarchy. The United Kingdom or Britain is also a monarchy. The head of the state is the king or queen, but he or she has only nominal power and the real power of the executive is exercised by the prime minister. The legislative power is exercised by the parliament. This means that all the laws are made by the elected parliament, and executive power is exercised by the Council of Ministers led by the prime minister. So while Britain has a king, it really is, today, a parliamentary democracy. This kind of monarchy is called a constitutional monarchy.”
Why relevant
Provides a concrete example (United Kingdom) of a 'constitutional monarchy' where the monarch is head of state in name only and real executive power lies with the prime minister.
How to extend
A student could compare other countries labeled 'constitutional' to see if their heads of state are nominal (like the UK) or substantial (like presidential systems) to judge the generality of the statement.
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 20: Prime Minister > Prime Minister > p. 207
Strength: 4/5
“In the scheme of parliamentary system of government provided by the constitution, the President is the nominal executive authority (de jure executive) and Prime Minister is the real executive authority (de facto executive). In other words, President is the head of the State while Prime Minister is the head of the government.”
Why relevant
Explains in a parliamentary system the President is a 'nominal' (de jure) executive while the Prime Minister is the 'real' (de facto) executive.
How to extend
Use this pattern to distinguish constitutional governments of the parliamentary type (head of state nominal) from systems where the head of state is the real executive (presidential), testing the statement across system types.
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 92: World Constitutions > 2021 TEST PAPER > p. 762
Strength: 3/5
“UPSC Questions on Indian Polity (General Studies-Prelims 2013-2023)
(c) A Sovereign Secular Democratic Republic
(d) A Sovereign Socialist Secular Democratic Republic
17. Constitutional government means
(a) a representative government of a nation with federal structure
(c) a government whose Head enjoys real powers
(d) a government limited by the terms of the Constitution
18. Consider the following statements in respect of Bharat Ratna and Padma Awards:
Which of the above statements are not correct?
• (a) 1 and 2 only • (b) 2 and 3 only • (c) 1 and 3 only • (d) 1, 2 and 3”
Why relevant
Includes a multiple-choice item where 'Constitutional government' is contrasted between 'head enjoys real powers' and 'government limited by the terms of the Constitution', indicating these are competing concepts in exam treatment.
How to extend
A student could take this as a prompt to examine which of these definitions aligns with standard constitutional theory and with examples of countries called 'constitutional governments'.
Statement 4
Does "constitutional government" mean a government limited by the terms of the constitution?
Origin: Direct from books
Fairness: Straightforward
Book-answerable
From standard books
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 3: Concept of the Constitution > II Definition > p. 25
Presence: 5/5
“It means government according to rule as opposed to arbitrary government; it means government limited by the terms of a constitution, not government limited only by the desires and capacities of those who exercise power." 14. ¥bema: A form of government can only be classified as constitutional when the rulers are subject to a body of rules and principles, which limit the exercise of their power.”
Why this source?
- Explicitly defines 'constitutional government' as government limited by the terms of a constitution.
- Contrasts constitutional rule with arbitrary government, emphasizing rule-bound authority.
- Adds that rulers must be subject to rules and principles that limit exercise of power.
Indian Constitution at Work, Political Science Class XI (NCERT 2025 ed.) > Chapter 1: CONSTITUTION: WHY AND HOW? > So the third function of a constitution is to set some limits on what a government can impose on its citizens. These limits are fundamental in the sense that government may never trespass them. > p. 6
Presence: 4/5
“Constitutions limit the power of government in many ways. The most common way of limiting the power of government is to specify certain fundamental rights that all of us possess as citizens and which no government can ever be allowed to violate. The exact content and interpretation of these rights varies from constitution to constitution. But most constitutions will protect a basic cluster of rights. Citizens will be protected from being arrested arbitrarily and for no reason. This is one basic limitation upon the power of government. Citizens will normally have the right to some basic liberties: to freedom of speech, freedom of conscience, freedom of association, freedom to conduct a trade or business etc.”
Why this source?
- Explains that constitutions set fundamental limits on what government can impose on citizens.
- Highlights specific protections (e.g., against arbitrary arrest, basic liberties) as limits on government power.
Indian Polity, M. Laxmikanth(7th ed.) > Chapter 27: Judicial Review > p. 297
Presence: 4/5
“"As long as some Fundamental Rights exist and are a part of the Constitution, the power of judicial review has also to be exercised with a view to see that the guarantees afforded by these Rights are not contravened"." "The Constitution is supreme lex, the permanent law of the land, and there is no branch of government above it. Every organ of government, be it the executive or the legislature or the judiciary, derives its authority from the Constitution and it has to act within the limits of its authority" It is the function of the Judges, may their duty, to pronounce upon the validity of laws.”
Why this source?
- States the Constitution is the supreme law and no branch of government is above it.
- Affirms that every organ of government derives authority from the Constitution and must act within its limits.
Pattern takeaway:
UPSC has a dedicated slot for 'Political Theory' definitions (Liberty, Rights, State, Democracy). These cannot be solved by reading current affairs; they require deep reading of NCERT Class XI Political Theory to understand the *essence* of concepts, not just their Indian application.
How you should have studied
- [THE VERDICT]: Sitter. Direct lift from NCERT Class XI ('Constitution: Why and How?') and Laxmikanth Chapter 3 (Concept of Constitution).
- [THE CONCEPTUAL TRIGGER]: Political Theory > The concept of 'Constitutionalism' vs. 'Constitution'.
- [THE HORIZONTAL EXPANSION]: Memorize these core theoretical distinctions: Rule of Law (Dicey) vs. Rule by Law; Procedural vs. Substantive Democracy; Negative Liberty (absence of restraint) vs. Positive Liberty (conditions for growth); Separation of Powers (Montesquieu).
- [THE STRATEGIC METACOGNITION]: The trap is Option A. Students confuse 'Features of the Indian Constitution' (Federal/Representative) with the 'Definition of Constitutional Government'. Always ask: 'Does this definition apply to the UK (Unitary) or USA (Presidential)?' If not, it's too narrow.
Concept hooks from this question
👉 Federal vs Unitary Constitution
💡 The insight
Distinguishes systems by the nature of the relationship between the national government and regional governments.
High-yield for polity questions: helps classify countries, compare constitutional arrangements, and answer questions on distribution of authority and autonomy. Connects to topics on centre-state relations, emergency provisions, and features of constitutions.
📚 Reading List :
- Laxmikanth, M. Indian Polity. 7th ed., McGraw Hill. > Chapter 3: Concept of the Constitution > D I Federal and Unitary > p. 24
- Indian Polity, M. Laxmikanth(7th ed.) > Chapter 14: Federal System > Federal System > p. 137
🔗 Anchor: "Does "constitutional government" mean a representative government of a nation wi..."
👉 Division of Powers and Residuary Powers
💡 The insight
Explains how legislative and executive powers are allocated between the centre and states, including where residuary powers lie.
Essential for questions on federalism, legislative competence, and amendment powers; enables answering scenario-based questions on conflicts of jurisdiction and constitutional amendments.
📚 Reading List :
- Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 16: India–Political Aspects > Indian Federalism > p. 4
- Indian Polity, M. Laxmikanth(7th ed.) > Chapter 92: World Constitutions > AMERICAN CONSTITUTION > p. 673
🔗 Anchor: "Does "constitutional government" mean a representative government of a nation wi..."
👉 Written Constitution and Rigidity
💡 The insight
Identifies that federal systems typically rest on a written constitution and include specific amendment/entrenchment rules.
Important for distinguishing federal characteristics from unitary ones and for questions on constitutional supremacy, amendment processes, and the durability of constitutional arrangements.
📚 Reading List :
- Laxmikanth, M. Indian Polity. 7th ed., McGraw Hill. > Chapter 14: Federal System > Federal System > p. 137
- Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 16: India–Political Aspects > Federal States > p. 2
🔗 Anchor: "Does "constitutional government" mean a representative government of a nation wi..."
👉 Constitutional government = government limited by a constitution
💡 The insight
A constitutional government is one in which rulers are subject to a body of rules and principles that limit the exercise of their power.
High-yield for polity questions: distinguishes constitutionalism from arbitrary rule and underpins questions about separation of powers, judicial review, and limits on executive authority. Mastering this helps answer definition-based and comparison questions on forms of government.
📚 Reading List :
- Indian Polity, M. Laxmikanth(7th ed.) > Chapter 3: Concept of the Constitution > II Definition > p. 25
- Laxmikanth, M. Indian Polity. 7th ed., McGraw Hill. > Chapter 3: Concept of the Constitution > II Definition > p. 25
🔗 Anchor: "Does "constitutional government" mean a government whose head of state enjoys on..."
👉 Nominal vs real executive (de jure vs de facto)
💡 The insight
In many parliamentary systems the head of state is a nominal (de jure) executive while the head of government exercises real (de facto) executive power.
Essential for questions on roles of President/Monarch vs Prime Minister/Chief Minister; useful for interpreting constitutional provisions and exam items contrasting ceremonial and effective power.
📚 Reading List :
- Indian Polity, M. Laxmikanth(7th ed.) > Chapter 31: Chief Minister > Chief Minister > p. 325
- Democratic Politics-I. Political Science-Class IX . NCERT(Revised ed 2025) > Chapter 4: WORKING OF INSTITUTIONS > The President > p. 67
🔗 Anchor: "Does "constitutional government" mean a government whose head of state enjoys on..."
👉 Constitutional monarchy is a specific form where the monarch is ceremonial
💡 The insight
A constitutional monarchy features a monarch with largely nominal functions while legislative and executive powers rest with elected bodies and leaders.
Helps distinguish specific systems (e.g., UK, Japan) from the broader concept of constitutional government; valuable for comparative polity questions and identifying which features are universal versus system-specific.
📚 Reading List :
- Exploring Society:India and Beyond ,Social Science-Class VII . NCERT(Revised ed 2025) > Chapter 9: From the Rulers to the Ruled: Types of Governments > b. Constitutional monarchy > p. 201
- Indian Polity, M. Laxmikanth(7th ed.) > Chapter 92: World Constitutions > JAPANESE CONSTITUTION > p. 684
- Indian Constitution at Work, Political Science Class XI (NCERT 2025 ed.) > Chapter 4: EXECUTIVE > Semi-Presidential Executive in Sri Lanka > p. 82
🔗 Anchor: "Does "constitutional government" mean a government whose head of state enjoys on..."
👉 Constitutionalism = Limited Government
💡 The insight
Constitutional government is rooted in the idea of limiting governmental powers rather than concentrating substantial powers in a single head of state.
High-yield for polity questions: distinguishes between mere existence of a constitution and the principle of constitutionalism; connects to checks and balances, rule of law and protection of liberties. Mastery helps answer questions on the nature and purpose of constitutions, limits on state power, and comparisons with authoritarian regimes.
📚 Reading List :
- Indian Polity, M. Laxmikanth(7th ed.) > Chapter 3: Concept of the Constitution > II I Meaning > p. 25
- Indian Polity, M. Laxmikanth(7th ed.) > Chapter 3: Concept of the Constitution > MEANING > p. 22
🔗 Anchor: "Does "constitutional government" mean a government whose head of state enjoys re..."
The logical sibling is 'Constitutional Morality'. Since they asked about Constitutional Government (Limited Govt), the next step is the spirit of adherence to it. Key fact: Ambedkar called it a 'top-dressing' on Indian soil, implying it must be cultivated, unlike in established democracies.
Use the 'Counter-Example Test'.
Option A says 'Federal'. Is the UK a constitutional government? Yes. Is it Federal? No (Unitary). Eliminate A.
Option B says 'Nominal Head'. Is the USA a constitutional government? Yes. Is the President nominal? No (Real power). Eliminate B.
Option D applies to all. Mark D.
Links directly to GS2 Mains: 'Basic Structure Doctrine'. The Basic Structure is essentially the judiciary enforcing 'Constitutionalism' (Option D) by preventing Parliament from using its amendment power to become unlimited or arbitrary.