Final answer:
The correct description of the speed of light is that orange and violet light travel at the same speed in a vacuum, which is a constant for all colors of light, independent of the motion of the source or the observer.
Step-by-step explanation:
The student's question asks which statement correctly describes the speed of light. The correct answer to the question is d) Orange light speed = Violet light speed. This is because the speed of light in a vacuum is a constant for all colors of light, and is approximately 3.00×108 meters per second. While the speed of light can vary in different media (like glass or water), within the same medium, it does not depend on the color of the light. Colors like orange and violet have different frequencies and wavelengths, but when they are in the same medium, such as a vacuum, their speeds are equal. This is supported by the principle that the speed of light is independent of the motion of the source relative to the observer, as well as by Einstein's theory of relativity, which demonstrates that the speed of light in a vacuum is the same for all observers, regardless of their relative motion or the motion of the light source.