Correct Option: C
The real powers at the central level are exercised by the Prime Minister and the Council of Ministers. The President is the nominal head, while the Prime Minister leads the functioning of the government.
Option A: President of India
Incorrect. The President is the constitutional head but acts on the advice of the Council of Ministers.
Option B: Vice-President of India
Incorrect. The Vice-President has a mainly ceremonial role and presides over the Rajya Sabha.
Option C: Prime Minister of India
Correct. He is the de facto executive authority and head of government.
Option D: Chief Ministers
Incorrect. Chief Ministers are heads of state governments, not the central government.