The Volume V of a Right Circular Cone Varies Jointly

Multiple Choice

The volume V of a right circular cone varies jointly as the square of the radius r and the height h . Tell what happens to V when r is doubled.

A) V is 4 times as large.
B) V is 3 times as large.
C) V is 2 times as large.
D) V is 9 times as large.
E) V is 6 times as large.