Question

A comet is a

Answer 1

With the options given, the best answer is a small object made of ice and dust that orbits the sun and forms a coma as it approaches the sun.

Answer 2

A comet is a small object made of ice and dust that orbits the Sun and forms a coma as it approaches the Sun.

A comet is a small celestial body consisting mainly of ice, dust and gas in a (usually very eccentric) orbit around the sun and forming a coma, and sometimes having a tail of matter (gas and dust particles) blown back from it by the solar wind as it approaches the sun.