The President's Role in Foreign Policy Increased Largely Because

The president's role in foreign policy increased largely because

A) Congress proved so inept in foreign affairs that the American people demanded a change.
B) America became more of a world power.
C) of the need to coordinate national economic policy and foreign policy,a task to which the presidency was well suited.
D) of the desire of U.S.business to expand into Latin America and Asia,which required executive action at the highest level.
E) of attitudes held by the American public.