The Integral $\int \cos ( 2 x ) \cos ( 3 x ) d x$

Multiple Choice

The integral $\int \cos ( 2 x ) \cos ( 3 x ) d x$ is

A) $\frac { 5 \sin x - \sin ( 5 x ) } { 10 } + C$
B) $\frac { - 5 \sin x - \sin ( 5 x ) } { 10 } + C$
C) $\frac { 5 \sin x + \sin ( 5 x ) } { 10 } + C$
D) $\frac { - 5 \sin x + \sin ( 5 x ) } { 10 } + C$
E) $\frac { \sin x - 5 \sin ( 5 x ) } { 10 } + C$