Two plane mirrors OA and OB are inclined at an angle $$\theta$$ as shown in the figure. A ray of light incident parallel to BO strikes the mirror OA at point P. It gets reflected from mirror OA and then reflected from mirror OB, the ray finally emerges parallel to OA. The value of angle $$\theta$$ is

A

$$90^\circ$$

B

$$60^\circ$$

C

$$45^\circ$$

D

$$30^\circ$$