The Area of One Leaf of Rose $r = 2 \cos ( 2 \theta )$

Multiple Choice

The area of one leaf of rose $r = 2 \cos ( 2 \theta )$ is

A) $\frac { \pi } { 2 }$
B) $\pi$
C) $\frac { 3 \pi } { 2 }$
D) $\frac { 5 \pi } { 2 }$
E) $2 \pi$