$$\lim_{x \rightarrow a}\frac{(\sqrt{3x - a} - \sqrt{(x + a)})}{(x - a)} =$$

A

$$\frac{1}{a}$$

B

$$\frac{1}{\sqrt{a}}$$

C

$$\frac{1}{2a}$$

D

$$\frac{1}{\sqrt{2a}}$$