Simplify the following:
$$\frac{\cos x - \sqrt{3} \sin x}{2}$$

A

$$\cos (\frac{\pi}{3} - x)$$

B

$$\sin (\frac{\pi}{3} + x)$$

C

$$\sin (\frac{\pi}{3} - x)$$

D

$$\cos (\frac{\pi}{3} + x)$$