Light can travel through a medium, but it does not require a medium.

a. True

b. False

That's true. Light can travel through glass, water or jello,

but it also gets here very effectively through empty space,

from the sun and stars.

True.

Light is a part of electromagnetic radiation or spectrum which can even travel through vacuum or through any medium. It does not require a medium to travel or particles of a medium to transfer energy through that medium but can also travel through a medium. Its speed in vacuum is different from that when travelling through a medium.