Find the Integral $\int x e^{3 x} d x$ A) $\frac{1}{3}(3 x-1) e^{3 x}+C$

Multiple Choice

Find the integral. $\int x e^{3 x} d x$

A) $\frac{1}{3}(3 x-1) e^{3 x}+C$
B) $\frac{1}{9}(3 x-1) e^{3 x}+C$
C) $\frac{1}{6} x^{2} e^{3 x}+C$
D) $\frac{1}{4} x e^{4 x}+C$