Give the Exact Value of the Expression $\arccos \left( \cos \frac { 7 \pi } { 6 } \right)$

Give the exact value of the expression.
- $\arccos \left( \cos \frac { 7 \pi } { 6 } \right)$

A) $\frac { \pi } { 3 }$
B) $\frac { 5 \pi } { 6 }$
C) $\frac { 4 \pi } { 3 }$
D) $\frac { \pi } { 6 }$