What is mostly made up of ice?

A - Meteors

B - Asteroids

or

C - Comets

Answer: Comets

Explanation: Comets are made mostly up of rock. A comet is like a giant dirty snowball, the size of a town or city. It is made up of ice, dust, and small pieces of rock. As a comet gets closer to the sun, it starts to melt and it becomes surrounded by a lot of gas and dust.