Answer :
A vacuum doesn't contain a medium. Light, which is an electromagnetic
wave and doesn't require a medium, will travel there. Sound, which is a
mechanical wave and requires a medium, will not travel there.
(You can see the light of the sun and other stars, which travels to us through
space. Astronauts can't hear the sound of each others' voices when they're
standing together on the moon because there's no medium between them,
so they have to use radio even to go only a few feet.)
Answer: A Medium is not necessary
Is C
Explanation: In contrast, light waves CAN travel through a vacuum, and do not require a medium. In empty space, the wave does not dissipate grow smaller no matter how far it travels, because the wave is not interacting with anything else. However, light can also travel within some materials, like glass and water.