Use Fundamental Identities to Simplify the Expression Below and Then $\sin \left( \frac { \pi } { 2 } - x \right) \csc x$

Multiple Choice

Use fundamental identities to simplify the expression below and then determine which of the following is not equivalent. $\sin \left( \frac { \pi } { 2 } - x \right) \csc x$

A) ​ $\tan x$
B) ​ $\cos \mathrm { x } \csc \mathrm { x }$
C) ​ $\cot x$
D) ​ $\frac { \cos x } { \sin x }$
E) ​ $\frac { 1 } { \tan x }$