Which traditional Earth-centered system is debated against Copernicanism in Galileo's Dialogue?

Which traditional Earth-centered system is debated against Copernicanism in Galileo’s Dialogue? The opposing system is the Ptolemaic system.

Galileo’s Dialogue Concerning the Two Chief World Systems compares Copernican heliocentrism with the Ptolemaic system, the traditional geocentric model associated with the astronomer Claudius Ptolemy. In the Ptolemaic framework, Earth remains stationary at the center while the Sun, Moon, planets, and stars move around it through nested circular motions.

To reproduce observed planetary movements, Ptolemaic astronomy used devices such as deferents and epicycles. Copernicus reorganized the arrangement by placing the Sun at the center and making Earth one of the planets. Galileo’s telescope supplied important evidence favoring a changing and non-Earth-centered heavens, including the phases of Venus and the moons orbiting Jupiter.

A common complication is the Tychonic system, another geocentric-looking model in which the Sun orbits Earth while the other planets orbit the Sun. It could account for some observations available in Galileo’s era, but it is not the named traditional system presented in the Dialogue’s title and central comparison. The quiz’s canonical answer is therefore Ptolemaic system.