Determine Which of the Following Are Trigonometric Identities $\frac { \cos ( 4 x ) - \cos ( 2 x ) } { 2 \tan ( 3 x ) } = - \tan ( x )$

Multiple Choice

Determine which of the following are trigonometric identities.
$\frac { \cos ( 4 x ) - \cos ( 2 x ) } { 2 \tan ( 3 x ) } = - \tan ( x )$
$\frac { \cos ( 3 x ) - \cos ( x ) } { \sin ( 3 x ) - \sin ( x ) } = - \tan ( 2 x )$
$\frac { \cos ( 6 x ) - \cos ( 2 x ) } { \sin ( 4 x ) + \sin ( 2 x ) } = - \tan ( 3 x$

A) II is the only identity.
B) I is the only identity.
C) I, II, and III are identities.
D) None are identities.
E) I and III are the only identities.