Which one of the following writs is issued by the Supreme Court of India in case of illegal detention ?

The correct answer is (a) Habeas Corpus.

Habeas corpus is a writ that is issued to bring a person before a court to determine whether they are being held lawfully. It is a powerful tool that can be used to protect people from unlawful detention.

The other options are:

• Mandamus: A writ that orders a public official to perform a legal duty.
• Prohibition: A writ that prohibits a lower court from hearing a case.
• Quo-warranto: A writ that asks a court to determine whether someone has the right to hold a public office.

I hope this helps! Let me know if you have any other questions.