The Writers of the Constitution Established a Federal System of Government

The writers of the Constitution established a federal system of government in part because

A) the states already existed as established entities and had to be preserved.
B) few states in history had successfully established unitary governments.
C) Locke and Montesquieu had concluded it was superior to other systems of government.
D) the British political system was based on the federal principle.
E) the states would be valuable sources of revenue for a federal government.