A ray is incident at an angle of incidence i on one surface of a small angle prism (with angle of prism A) and emerges normally from the opposite surface. If the refractive index of the material of the prism is $\mathrm{\mu }$ then the angle of incidence is nearly equal to :  

• A

  $\frac{2\mathrm{A}}{\mathrm{\mu }}$

• B

  $\mathrm{\mu A}$

• C

  $\frac{\mathrm{\mu A}}{2}$

• D

  $\frac{\mathrm{A}}{2\mathrm{\mu }}$