Consider a Comet in a Long, Thin Elliptical Orbit with a Semimajor

Multiple Choice

Consider a comet in a long, thin elliptical orbit with a semimajor axis of one astronomical unit. What can be said about the sidereal period of this comet?

A) The sidereal period will be less than 1 year.
B) The sidereal period will be 1 year.
C) The sidereal period will be more than 1 year.
D) It is not possible to determine the comet's sidereal period without knowing the eccentricity of its orbit.