Let $f ( x ) = e ^ { x } \cosh x$

Multiple Choice

Let $f ( x ) = e ^ { x } \cosh x$ Then $f ^ { \prime } ( x )$ is

A) $e ^ { x } ( \sinh x + \cosh x )$
B) $e ^ { x } \sinh x$
C) $e ^ { x } ( \sinh x - \cosh x )$
D) $e ^ { x } ( - \sinh x + \cosh x )$
E) $e ^ { x } ( - \sinh x - \cosh x )$