Which development was the first major change to ancient models of the solar system?

Question

the placement of the Sun at the center of the solar system
the placement of the Sun at the center of the solar system

the choice to make elliptical rather than circular orbits
the choice to make elliptical rather than circular orbits

the placement of some planets closer to the center of the solar system
the placement of some planets closer to the center of the solar system

the choice to place stars far from Earth

Answer 1

the placement of the Sun at the center of the solar system.