One phenomenon that the geocentric models struggled to explain was ____.
A) sunspots
B) the rotation of Earth
C) retrograde motion
D) parallax
E) epicycles

Question

Quizplus · Accepted Answer

Geocentric models struggled to explain retrograde motion, which is the apparent backward movement of planets as observed from Earth. This was more naturally explained by the heliocentric model, where planets orbit the Sun.

One Phenomenon That the Geocentric Models Struggled to Explain Was