Let $f ( x ) = \ln ( \tan x )$

Multiple Choice

Let $f ( x ) = \ln ( \tan x )$ Then $f ^ { \prime } ( x )$ is

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