Evaluate $$\int_{-\infty}^{\infty} x^{4} f(x) dx$$, where $$f(x)=\frac{1}{\sqrt{2 \pi}}e^{-\left(\frac{x^{2}}{2}\right)}, x \in(-\infty,\infty)$$

A

3

B

$$3 \sqrt{\pi}$$

C

$$\sqrt{3} \pi$$

D

$$3 \pi$$