TI1e exit surface of a prism with refractive index n is coated with a material having refractive index $$\frac{n}{2}$$. When this prism is set for minimum angle of deviation, it exactly meets the condition of critical angle. The prism angle is ___ .

A

$$60^{\circ}$$

B

$$30^{\circ}$$

C

$$15^{\circ}$$

D

$$45^{\circ}$$