Factor; Then Use Fundamental Identities to Simplify the Expression Below $\cot ^ { 2 } \alpha - \cot ^ { 2 } \alpha \cos ^ { 2 } \alpha$

Multiple Choice

Factor; then use fundamental identities to simplify the expression below and determine which of the following is not equivalent.
$\cot ^ { 2 } \alpha - \cot ^ { 2 } \alpha \cos ^ { 2 } \alpha$

A) $\cos ^ { 2 } \alpha$
B) $\sin ^ { 2 } \left( \frac { \pi } { 2 } - \alpha \right)$
C) $1 - \sin ^ { 2 } \alpha$
D) $\cot ^ { 2 } \alpha$
E) $\frac { 1 } { \sec ^ { 2 } \alpha }$