Use Integration by Parts to Find the Integral $\int 3 x e^{x} d x$

Multiple Choice

Use integration by parts to find the integral.
- $\int 3 x e^{x} d x$

A) $3 x e^{x}-3 e^{x}+C$
B) $3 e^{x}-e^{x}+C$
C) $3 e^{x}-3 x e^{x}+C$
D) $x e^{x}-3 e^{x}+C$