Evaluate Exactly $\sec \left( \cos ^ { - 1 } \left( \frac { 1 } { 2 } \right) \right)$

Multiple Choice

Evaluate exactly.
- $\sec \left( \cos ^ { - 1 } \left( \frac { 1 } { 2 } \right) \right)$

A) 2
B) -1
C) $\frac { - 1 } { 2 }$
D) $- 2$