The correct answer is D) They exist to help the president administer federal policies.
All parts of the federal bureaucracy share the following characteristic "They exist to help the president administer federal policies."
We are talking about the thousands of people that work in the administrative body called the US bureaucracy. These people work for the executive branch, in the many departments such as the Department of Commerce, the Department of State, the Department of Labour, the Department of the Treasury, the Department of Defense, or Executive Agencies such as the Federal Burau of Investigation.
