Final answer:
Light reflecting from a smooth surface does not change its speed, frequency, or wavelength. The correct answer regarding changes during reflection is 'b. None of these'.
Step-by-step explanation:
Light reflecting from a smooth surface undergoes a change in neither speed, frequency nor wavelength. Therefore, the correct answer is b. None of these. When a light beam reflects off a surface, it obeys the law of reflection, with the angle of incidence equaling the angle of reflection; however, its speed, frequency, and wavelength remain unchanged. The change in speed only occurs when light transitions between media of different optical densities, such as from air to water, which is a case of refraction rather than reflection.
When light reflects from a smooth surface, the wavelength of the light changes, but the speed does not. This is because the speed of light is constant in a vacuum and in a transparent material, and does not depend on the frequency or wavelength of the light. The frequency of the light also remains unchanged upon reflection.