Explanation:

- Article 21 is indeed the correct option. It guarantees the protection of life and personal liberty to individuals in India. It states, "No person shall be deprived of his life or personal liberty except according to procedure established by law."

- Article 250 permits the Parliament to legislate on State List subjects during a national emergency.

- Article 370 granted special autonomy to Jammu and Kashmir, which has since been revoked.

- Article 57 relates to the eligibility for re-election of the President of India.