Answer:
3rd diagram
Step-by-step explanation:
From the laws of reflection, we understood that the angle of incidence in equal to the angle of reflection.
For example, if a ray of light strikes a mirror at 60°, it reflected at the same angle (i.e 60°)
Considering the diagram given in the question above,
The ray of light strikes the mirror at 40°. Therefore, the light will be reflected with the same angle (i.e 40°)
Thus, the 3rd diagram gives the correct answer to the question.