Answer:
Earth is at the center.
Step-by-step explanation:
The geocentric model is a model system that explains how the planets in the solar system move around.
Ptolemy established the geocentric concept, which states that the earth is at the center of the solar system and that other celestial bodies, including planets and stars, rotate around it.
Nicolas Copernicus invalidated this model system by explaining that the sun is at the center of the solar system and that the planets rotate around it.