The statement is b. False.
Comets do not orbit around the Sun in a short, circular paths, but they have very large and elongated, elliptical paths. Their paths are not like those of the planets where the distance between the planet and the Sun is kept in pretty much the same level (it differs throughout the year but not drastically), instead their paths make them go very close to the Sun at one point, and than go very far from the Sun at other point.