Evaluate the Integral $\int x \sin 3 x \cos 3 x d x$

Multiple Choice

Evaluate the integral. $\int x \sin 3 x \cos 3 x d x$

A) $-\frac{1}{9}(\cos 9 x-9 x \sin 9 x) +C$
B) $\frac{1}{18}(\sin 3 x-3 x \cos 3 x) +C$
C) $\frac{1}{9}(\sin 9 x-49 \cos 9 x) +C$
D) $-\frac{1}{18}(\sin 18 x-18 x \cos 18 x) +C$
E) None of these