Two identical particles each of mass $$m$$ go round a circle of radius $$a$$ under the action of their mutual gravitational attraction. The angular speed of each particle will be :

A

$$\sqrt{\frac{Gm}{a^3}}$$

B

$$\sqrt{\frac{Gm}{8a^3}}$$

C

$$\sqrt{\frac{Gm}{4a^3}}$$

D

$$\sqrt{\frac{Gm}{2a^3}}$$