Question

1. ptolemy believed that the universe was geocentric, or

a. earth - centered.
c. moon - centered.

b. concentric
d. sun - centered.

Explanation:

Ptolemy's geocentric model posits that the Earth is at the center of the universe. So the geocentric (Earth - centered) model is what he believed. Option A is Earth - centered, which matches the geocentric view. Option B (concentric) is not the right description for the center; Option C (moon - centered) is incorrect, and Option D (sun - centered) is the heliocentric model (supported by Copernicus, not Ptolemy).

Answer:

A. Earth - centered.