Use Geometry to Find the Exact Value Of $\int _ { - 2 } ^ { 2 } \sqrt { 4 - x ^ { 2 } } d x$

Multiple Choice

Use geometry to find the exact value of $\int _ { - 2 } ^ { 2 } \sqrt { 4 - x ^ { 2 } } d x$

A) $\pi$
B) $\pi$ /2
C) 4 $\pi$
D) 2 $\pi$