In an isosceles prism of prism angle `45^(@)`, it is found that when the angle of incidence is same as the prism angle, the emergent ray grazes the emergent surface. Find the refractive index of the material of the prism.For what angle of incidence the angle of deviation will be minimum ?
A. `(2)^(1//2)`
B. `(3)^(1//2)`
C. `2`
D. `(5)^(1//2)`