In the given figure, $$a=15 \frac{m}{s^2}$$ represents the total acceleration of a particle moving in the clockwise direction in a circle of radius R=2.5 m at a given instant of time. The speed of the particle is

A

$$5.0 \frac{m}{s}$$

B

$$5.7 \frac{m}{s}$$

C

$$6.2 \frac{m}{s}$$

D

$$4.5 \frac{m}{s}$$