Correct Option: C

A comet is a small, icy celestial body that orbits around the sun. It is made up of a nucleus (solid, frozen ice, gas and dust), a gaseous coma (water vapor, CO2, and other gases) and a long tail (made of dust and ionized gases). The tail develops when the comet is near the Sun. The tail can be up to 250 million km long, and is most of what we see. Comets are only visible when they’re near the sun in their highly eccentric orbits.