Suppose a Comet Orbits the Sun on a Highly Eccentric

Multiple Choice

Suppose a comet orbits the Sun on a highly eccentric orbit with an average (semimajor axis) distance of 1 AU. How long does it take to complete each orbit, and how do we know?

A) It depends on the eccentricity of the orbit, as described by Kepler's first law.
B) Each orbit takes about 1 year, which we know from Kepler's third law.
C) Each orbit should take about 2 years, because the eccentricity is so large.
D) It depends on the eccentricity of the orbit, as described by Kepler's second law.