Phobos and Deimos, the Two Moons of Mars, Rotate on Their

Multiple Choice

Phobos and Deimos, the two moons of Mars, rotate on their axes:

A) so that they always have the same sides facing each other as they orbit Mars.
B) with no particular relationship to their revolutionary periods, that is, nonsynchronously.
C) to maintain the same face toward the Sun at all times, because of tidal forces.
D) synchronously, keeping one face toward Mars at all times.