Evaluate the Following Expression $$( 1 + \sin \alpha ) ( 1 - \sin \alpha )$$

Multiple Choice

Evaluate the following expression. $$( 1 + \sin \alpha ) ( 1 - \sin \alpha )$$

A) $- \cos ^ { 2 } \alpha$
B) $\sin ^ { 2 } \alpha$
C) $\cos ^ { 2 } \alpha$
D) $- 2 \sin ^ { 2 } \alpha$
E) $2 \cos ^ { 2 } \alpha$