The Earth and the Solar System — practice question

Which of the following statements about the orbits of comets is correct?

• AComets have elliptical orbits and the Sun is at the centre of the orbit.
• BComets have elliptical orbits and the Sun is not at the centre of the orbit.
• CComets have circular orbits and the Sun is at the centre of the orbit.
• DComets have circular orbits and the Sun is not at the centre of the orbit.