Consider an equilateral prism (refractive index $$\sqrt{2}$$). A ray of light is incident on its one surface at a ce1tain angle $$i$$. If the emergent ray is found to graze along the other surface then the angle of refraction at the incident surface is close to ______.

A

$$20^{o}$$

B

$$30^{o}$$

C

$$40^{o}$$

D

$$15^{o}$$