$$\lim_{x \rightarrow 2a} \frac{\sqrt{x} - \sqrt{2a} + \sqrt{x - 2a}}{\sqrt{x^2 - 4a^2}} =$$

A

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

B

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

C

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

D

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