Explanation:

- The correct answer is option 1: Reservation for OBC.

- The Supreme Court’s judgement in the Indira Sawhney case, often referred to as the Mandal Commission case, is related to the reservation policies for the Other Backward Classes (OBC) in India.

- The case examined the validity of reservations and the extent of the state's power to implement them.

- Option 2: Reservation for Scheduled Castes is a separate issue, predominantly considered under Article 341 of the Indian Constitution.

- Option 3: Reservation for Minorities involves entirely different criteria and legal discussions.

- Option 4: Reservation for Scheduled Tribes deals with provisions under a different constitutional framework, primarily through Article 342.