Find the Exact Value of the Composition $\arccos \left( \cos \frac { \pi } { 2 } \right)$

Multiple Choice

Find the exact value of the composition.
- $\arccos \left( \cos \frac { \pi } { 2 } \right)$

A) $\frac { \pi } { 2 }$
B) $\pi$
C) 0
D) $\frac { \pi } { 3 }$