The correct answer is D) inherent.
The powers that the framers of the Constitution felt existed and were expected to be held by the National government due to historical precedence and common practice were called inherent.
The inherent powers are the ones that the President of the United States need to correctly perform their duties. He cannot be expected to act swiftly in every time he needs to receive authorization from Congress. So although not mentioned in the Constitution, the President can make decisions on his own. An example of inherent powers is the faculty that the President has to sign Executive Orders to manage the operations of the executive office and the federal government. These executive orders have the force of law.
The other options of the question were a) expressed, b) implied, and c) intended.