Evaluate the Given Quantity, but Do Not Use a Calculator $\cos ^ { - 1 } \left( - \frac { 1 } { 2 } \right)$

Multiple Choice

Evaluate the given quantity, but do not use a calculator or table. $\cos ^ { - 1 } \left( - \frac { 1 } { 2 } \right)$

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