Differentiate the Function $$y = e ^ { \cos 3 x }$$

Multiple Choice

Differentiate the function. Select the correct answer.
$$y = e ^ { \cos 3 x }$$

A) $- e ^ { \cos 3 x } \sin 3 x$
B) $- 3 e ^ { \cos 3 x } \sin 3 x$
C) $- 3 e ^ { \cos 3 x } \sin x$
D) $e ^ { \cos 3 x } \sin 3 x$