What happens to a wave during reflection?

When a wave undergoes reflection, it bounces back after striking a surface. This phenomenon occurs when a wave encounters a boundary between two different media or a reflective surface. The angle at which the wave hits the surface, known as the angle of incidence, is equal to the angle at which it reflects away from the surface, known as the angle of reflection. This principle is a fundamental concept in wave behavior and can be observed with various types of waves, including sound waves, light waves, and water waves.

In contrast, a wave may slow down or change medium when it refracts, not when it reflects. Additionally, waves spreading out is associated with diffraction rather than reflection. Overall, reflection is characterized specifically by the wave bouncing back, which is represented accurately by the correct choice.