The Supreme Court was unanimous in upholding the constitutional validity of

Correct option is C

The correct answer is (c) decriminalization of adultery under Section 497 of the Indian Penal Code.

Explanation

The case of Joseph Shine v. Union of India (2018) dealt with the constitutionality of Section 497 of the IPC (Adultery).

• Why (c) is correct: A 5-judge Constitution Bench was unanimous (5:0) in striking down Section 497. All judges agreed that the law was archaic, paternalistic, and violated Articles 14, 15, and 21. They ruled that the law treated a woman as the "property" of her husband and punished only the man, which was discriminatory and stripped women of their sexual autonomy.
• Why (a) is incorrect: In Justice K.S. Puttaswamy v. Union of India (2018), the Aadhaar Act was upheld by a 4:1 majority. Justice D.Y. Chandrachud delivered a famous dissent, arguing that passing the Act as a "Money Bill" was a fraud on the Constitution.
• Why (b) is incorrect: In Indian Young Lawyers Association v. State of Kerala (2018) (The Sabarimala Case), the court ruled in a 4:1 majority to allow the entry of women. Justice Indu Malhotra was the lone dissenter, arguing that "notions of rationality cannot be invoked in matters of religion."
• Why (d) is incorrect: In Bir Singh v. Delhi Jal Board (2018), the 5-judge bench had a 4:1 majority. While the majority held that a person migrant to another state cannot claim reservation there, Justice R. Banumathi dissented regarding the specific application of these rules to the Union Territory of Delhi.