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

a. True

b. False

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.

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.