Evaluate the Expression $\cos \left( ( 2 n + 1 ) \cdot 90 ^ { \circ } \right)$

Multiple Choice

Evaluate the expression.
- $\cos \left( ( 2 n + 1 ) \cdot 90 ^ { \circ } \right)$

A) 1
B) -1
C) Undefined
D) 0