Correct answer: D. a state governor
Explanation:
The Constitution of the United States asserts (in Article II, Section 1): "The executive Power shall be vested in a President of the United States of America." The role of chief executive means that he or she holds the primary administrative role in the federal government.
In state governments, the office of the governor is the head of the executive branch of state government. Each state's constitution will outline the powers of its executive, legislative, and judicial branches.