Answer:
The correct statement for comet is - ( a ) They have highly elliptical orbits around the sun
Explanation:
The comet is made up by the composition of dust , water , ice , rock and frozen gases like , the carbon dioxide , methane , ammonia and carbon monoxide .
Comet shows a process called outgassing , i.e. , the comet passes close to the sun , then they start to release gases , which is visible in the form of a comet's tail .
The comet and its tail glows by the sun and becomes visible when the comet passes through the solar system , because the dust partials reflects sunlight directly and the gas glows due to ionization process.
The orbital of comet is usually highly eccentric elliptical path .
