A ray of monochromatic light is incident on one refracting face of a prism of angle `75^(@)`. It passes through the prism and is incident on the other face at the critical angle. If the refractive index of the material of the prism is `sqrt(2)`, the angle of incidence on the first face of the prism is
A. `30^(@)`
B. `45^(@)`
C. `60^(@)`
D. `0^(@)`
