Light is described as having a dual wave-particle nature. Which piece of evidence provides support for the model of light as a particle? Young's double slit experiment showed that light waves show interference.
Light reflects when it hits a surface.
Light refracts when it moves from one medium to another.
Light does not need a medium to travel.

Hey

Your answer would be D (Light does not need a medium to travel.)

For a long time, people believed in what was called the aether. The aether was a medium in empty space which light would have traveled through. The reason why people thought this was that they didn't think it was possible for a wave (light) to travel in empty space. Of course, now we know that light is unusual in the sense that it doesn't require a medium because all other known types of waves do have mediums.

I wrote all that^, please read it if you want to know the reason why its d.

the total distance traveled by the car is

30km + 49km = 79 km .