Observers on Earth see occasional retrograde motion in the motion of
A) only the inner planets: Mercury and Venus.
B) only the outer planets: Mars and beyond.
C) all the planets.
D) all the planets and the Moon.

Question

Quizplus · Accepted Answer

Retrograde motion is observed in all planets as they appear to move backward in the sky from Earth's perspective due to the relative positions and motions of Earth and the other planets in their orbits.

Observers on Earth See Occasional Retrograde Motion in the Motion