$\frac{d^n}{dx^n} (e^x \sin x)$ is equal to :

Question

( A ) $2^{n/2} e^x \sin (x - \frac{nx}{4})$
( B ) $2^{n/2} e^x \cos (x - \frac{nx}{4})$
( C ) $2^{n/2} e^x \sin (x + \frac{nx}{4})$
( D ) $2^{n/2} e^x \cos (x + \frac{nx}{4})$