When the angle of elevation of the sun increases from 30$$^{\circ}$$ to 60$$^{\circ}$$ , the shadow of a post is diminished by 5 metres. Then the height of the post is

A

$$\frac{5\sqrt{3}}{2}$$

B

$$\frac{2\sqrt{3}}{2}$$

C

$$\frac{2}{5\sqrt{3}}$$

D

$$\frac{4}{5\sqrt{3}}$$