Answer:
The light from the flashlight hits a mirror on the wall.
Explanation:
When the light from the flashlight hits a mirror on the wall, what happened is called Reflection. Reflection of light, however, is a term that describes a change in direction of a light wave as it reflects off a surface from one medium to another (e.g reflected from a mirror back to a flashlight)
Hence, what could cause the light coming from the flashlight to stop moving in a straight line is option D: The light from the flashlight hits a mirror on the wall.
