What does the law of reflection state?

The law of reflection states that the angle of incidence is equal to the angle of reflection, with both angles measured from the normal line, which is perpendicular to the surface at the point of incidence. This means that when a wave, such as light, strikes a reflective surface, the angle at which it hits the surface (the angle of incidence) will be the same as the angle at which it bounces off (the angle of reflection). Both of these angles lie in the same plane that includes the normal line. This fundamental principle is crucial in understanding how mirrors and other reflective surfaces work, ensuring predictable behavior in optics.

In the context of the other options, they capitalize on different concepts that do not align with the law of reflection, thus helping clarify why they are incorrect. For instance, the relationship between the angles is incorrectly stated in the first option, and the third option confuses wave velocity with directionality, which does not pertain to the reflection theory. The final option misrepresents the conditions under which reflection takes place, as reflection can indeed occur across different media, not just in a single medium.