Two Flat Rectangular Mirrors Are Set Edge to Edge and Placed

Multiple Choice

Two flat rectangular mirrors are set edge to edge and placed perpendicular to a flat non-reflecting surface.A light ray that reflects from mirror 1 at angle $\theta$ M1 then strikes the second mirror and reflects at $\theta$ M2 such that the angle between the ray reaching mirror 1 and the ray leaving mirror 2 is 180 $\degree$ .The angle between the two mirrors is:

A) 0 $\degree$ .
B) 45 $\degree$ .
C) 90 $\degree$ .
D) 150 $\degree$ .
E) 235 $\degree$ .