The correct answer is C. Cabinet Secretary.
The Cabinet Secretary is the administrative head of the Cabinet Secretariat, which is the highest policy making body in the Indian government. The Cabinet Secretary is appointed by the Prime Minister and is responsible for providing administrative support to the Cabinet. The Cabinet Secretary also acts as the Secretary to the Cabinet Committees and is responsible for coordinating the work of the various ministries and departments of the government.
The Cabinet Minister is a member of the Cabinet, which is the highest decision-making body in the Indian government. The Cabinet Minister is appointed by the Prime Minister and is responsible for a particular ministry or department of the government. The Cabinet Minister is not the administrative head of the Cabinet Secretariat.
The Prime Minister is the head of the government of India. The Prime Minister is appointed by the President and is responsible for the day-to-day running of the government. The Prime Minister is not the administrative head of the Cabinet Secretariat.
The President is the head of state of India. The President is elected by an electoral college consisting of members of both houses of Parliament and the legislative assemblies of the states. The President is not the administrative head of the Cabinet Secretariat.