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

Multiple Choice

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

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