Which Statement Is True with Respect to the "Necessary and Proper

Which statement is true with respect to the "necessary and proper" clause?

A) It has given presidents broader power to conduct war.
B) It has decreased the amount of time members of Congress devote to casework.
C) it has added significantly to the authority of Congress to act in both domestic and foreign affairs.
D) it has had little effect on legislative powers of Congress.
E) it created the Congressional Budget Office and limited the president's power in the area of federal spending.