A ray of light is incident at an angle $i$ on an equilateral prism. If the ray emerges grazing the second face, find angle of refraction at first surface. Refractive index of prism $\sqrt { 2 }$.
(A) $10 ^ { \circ }$
(B) $15 ^ { \circ }$
(C) $30 ^ { \circ }$
(D) $45 ^ { \circ }$