What is the value of $$\cot (90 - x) \sin^4 (90 - x) + \cot (180 - x) \sin^4 (180 - x)$$?

A

$$\frac{(\cos 4x)}{4}$$

B

$$\frac{(\sin^2 2x)}{2}$$

C

$$\frac{(\cos^2 2x)}{2}$$

D

$$\frac{(\sin 4x)}{4}$$