Use the Half-Angle Formulas to Determine the Exact Value of the Given

Multiple Choice

Use the half-angle formulas to determine the exact value of the given trigonometric expression. $\cot \frac { 3 \pi } { 8 }$

A) $\cot \frac { 3 \pi } { 8 } = \sqrt { 2 } + 1$
B) $\cot \frac { 3 \pi } { 8 } = - \frac { \sqrt { 2 - \sqrt { 2 } } } { 4 }$
C) $\cot \frac { 3 \pi } { 8 } = \sqrt { 2 } - 1$
D) $\cot \frac { 3 \pi } { 8 } = \sqrt { 2 - \sqrt { 2 } }$
E) $\cot \frac { 3 \pi } { 8 } = \frac { \sqrt { 2 + \sqrt { 2 } } } { 4 }$