The refractive angle of prism is A. A ray is incident normally on one of the refracting faces of a prism and emerges out. If D be the deviation of the ray then refractive index of the material of the prism is—

Options

A. `sin((A + D)/2)/sin (A/2)`
B. `sin((A + D)/sin (A/2)`
C. `sin((A/2 + D)/sin (A/2)`
D. `sin(A - D)/sin A`