A particle is placed at the point $$A$$ of a frictionless track $$ABC$$ as shown in figure. It is gently pushed towards right. The speed of the particle when it reaches the point $$B$$ is: (Take $$g = 10 \text{ m s}^{-2}$$).

A

$$20 \text{ m s}^{-1}$$

B

$$\sqrt{10} \text{ m s}^{-1}$$

C

$$2\sqrt{10} \text{ m s}^{-1}$$

D

$$10 \text{ m s}^{-1}$$