Question

How does light travel?

A.Light only travels in a vacuum and travels faster when the sound source is moving.
B. Light only travels in a medium and light travels faster when a sound source is stationary.
C. Light can travel in a vacuum and the speed varies depending on whether the source is moving or stationary.
D. Light can travel in the air or a vacuum and the speed is constant whether the light source is stationary or moving.

Answer 1

The answer is D, it doesn't matter what it's going through, the speed of light is a universal constant.