The refractive index of the material of a prism is $$\sqrt{2}$$ and the angle of the prism is $$30^\circ$$.one of the two refracting surfaces of the prism is made a mirror inwards, by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface)if its angle of incidence on the prism is

A

zero

B

$$30^\circ$$

C

$$45^\circ$$

D

$$60^\circ$$