Evaluate the Expression $$\cot \left( - 90 ^ { \circ } \right)$$

Multiple Choice

Evaluate the expression.
- $$\cot \left( - 90 ^ { \circ } \right)$$

A) $- 1$
B) Undefined
C) $\frac { \sqrt { 2 } } { 2 }$
D) 0