Change the Cartesian Integral to an Equivalent Polar Integral, and Then

Multiple Choice

Change the Cartesian integral to an equivalent polar integral, and then evaluate.
- $$\int _ { - 2 } ^ { 2 } \int _ { - \sqrt { 4 - y ^ { 2 } } } ^ { \sqrt { 4 - y ^ { 2 } } } d x d y$$

A) $8 \pi$
B) $2 \pi$
C) $4 \pi$
D) $16 \pi$