The correct answer is option 2, the Indian Constitution. The Indian Constitution is considered the highest law of the land because it is the supreme legal document that sets out the framework and principles of governance for the entire country. It establishes the rights and duties of the citizens and outlines the powers and responsibilities of the government. The Constitution also provides for the separation of powers between the three branches of government - the legislature, the executive, and the judiciary, ensuring checks and balances. It also lays down the fundamental principles and values that govern the nation, such as democracy, equality, secularism, and justice. The Indian Constitution is the foundation of the legal system in India and any law that is inconsistent with it can be declared unconstitutional and invalid.