The reflected wave amplitude of the light wave would change when reflected from the surface of the medium.
A. amplitude
Step-by-step explanation:
Amplitude helps in understanding the brightness or intensity of light with other light waves of the same wavelength. It measures the energy the light wave carries.
When light waves reflect from the surface of a medium, reflection happens, only the direction of light waves gets changed. When a light ray falls on a surface, then it bounces back from the surface. Because of these reasons, the amplitude of light wave changes, keeping the other properties the same.