A particle is projected from a point $$O$$ with velocity $$u$$ at an angle of $$60^\circ$$ with the horizontal. When it is moving in a direction at right angles to its direction at $$O$$, its velocity then is given by

A

$$\frac{u}{3}$$

B

$$\frac{u}{2}$$

C

$$\frac{2u}{3}$$

D

$$\frac{u}{\sqrt{3}}$$