Find $\int \sec ( 3 x ) \tan ( 3 x ) d x$

Multiple Choice

Find $\int \sec ( 3 x ) \tan ( 3 x ) d x$

A) $\sec 3 x + C$
B) $\frac { 1 } { 2 } \sec ^ { 2 } 3 x + C$
C) $\frac { 1 } { 3 } \sec 3 x \tan 3 x + C$
D) $\frac { 1 } { 3 } \sec 3 x + C$