Which principle among the following was added to the Directive Principles of State Policy by the 42nd Amendment to the Constitution ?

Lists the four specific Directive Principles that the 42nd Amendment added — the list does not include 'equal pay for equal work'.

A student could compare this explicit post‑amendment list with the text of Article 39 before and after 1976 (or with the original Constitution) to see whether 'equal pay' was newly inserted or pre‑existing.

Explains that Article 39 (clauses a and d) already enjoins the State to secure equal right to work and 'equal pay for equal work' to men and women.

Use this to infer that 'equal pay' was part of Article 39 (a Directive Principle) and then check whether Article 39 itself was created earlier than 1976.

Explicitly states clause (d) provides for equal pay for equal work for both men and women, tying the phrase to an Article of the Directive Principles.

A student could look up the original text or an early edition of the Constitution to confirm the clause's presence before 1976.

Asserts that the Directive Principles (Article 39) secure to men and women equal right to adequate means of livelihood and equal pay for equal work, indicating the concept is located in Article 39.

This supports checking the historical adoption date of Article 39 to judge whether the 42nd Amendment was the origin of that clause.

Notes the 42nd Amendment gave primacy to Directive Principles over certain Fundamental Rights, showing the amendment altered status of DPs but not necessarily their content.

Use this pattern (amendment changing status vs. content) to distinguish whether the 42nd Amendment added new DP content or primarily changed constitutional hierarchy — then verify by comparing lists of DP additions.