Use the Fundamental Identities to Simplify the Expression $\cos \theta - \cos \theta \sin ^ { 2 } \theta$

Multiple Choice

Use the fundamental identities to simplify the expression.
- $\cos \theta - \cos \theta \sin ^ { 2 } \theta$

A) $\sec ^ { 2 } \theta$
B) $\cos ^ { 3 } \theta$
C) $\tan ^ { 2 } \theta$
D) $\sin \theta$