The correct answer is: C. The Ruler of the State.
Before the establishment of the High Court, the Ruler of the State functioned as the Final Authority in the administration of Justice in Jammu and Kashmir. The Ruler had the power to appoint and dismiss judges, and to review and revise their decisions. The Ruler also had the power to grant pardons and reprieves.
The Governor is the head of state of Jammu and Kashmir, but he does not have the power to function as the Final Authority in the administration of Justice. The President of India is the head of state of India, but he does not have the power to function as the Final Authority in the administration of Justice in Jammu and Kashmir.