B

Step 1: At point P, the angle of incidence is given as 30°. According to the law of reflection, the angle of reflection will also be 30°.
Step 2: The light ray then travels towards point Q. Since the walls are parallel, the angle of incidence at Q remains the same, giving a reflection angle again of 30°.
Step 3: The light ray next travels towards point R. As it reflects off the perpendicular wall, the angle of incidence changes to 60° (90° - 30°), making the angle of reflection at R also 60°.
Step 4: The ray continues to point S and again reflects off the parallel wall. The angle of incidence at S will remain 30°, leading to a reflection angle of 30° at S.
Step 5: Finally, the ray travels to point T, reflecting off the perpendicular wall again, resulting in an angle of incidence of 60° and a reflection angle of 60° at T.
Therefore, the angles of reflection at points Q, R, S, and T are 30°, 60°, 30°, and 60° respectively, thus matching option B.