Question

look at the diagram of the solar system. what observation did this geocentric model of the solar system help to explain? orbit speed the phases of venus retrograde motion the rising of the sun

Explanation:

The geocentric model used epicycles to explain the retrograde motion of planets, where planets seemed to move backward in the sky. It couldn't accurately explain orbit speed, the phases of Venus (which support the heliocentric model), and the rising of the Sun is better - explained by Earth's rotation rather than the geocentric model.

Answer:

C. retrograde motion