C) is the correct answer. The Constitution makes the President the chief administrator of the Federal Government.
The United States Constitution say in Article. II. - The Executive Branch Section 1 - The President that:
The Executive Power shall be vested in a President of the United States of America. He shall hold his Office during the Term of four Years…
The President is the Chief of state, Chief executive, Chief administrator, Chief diplomat, Commander in chief, Chief legislator, Chief of party, Chief citizen .
As chief administrator, the President is in charge of the executive branch of the federal government, so he is in the top of the bureaucracy.