Solve the Problem $$\sqrt { \frac { 1 + \cos 18 ^ { \circ } } { 1 - \cos 18 ^ { \circ } } }$$

Multiple Choice

Solve the problem.
- $$\sqrt { \frac { 1 + \cos 18 ^ { \circ } } { 1 - \cos 18 ^ { \circ } } }$$

A) $\tan 9 ^ { \circ }$
B) $\cos 9 ^ { \circ }$
C) $\cot 9 ^ { \circ }$
D) $\sin 9 ^ { \circ }$