The beginning of modern astronomy can be traced back to Nicolaus Copernicus and his book, On the Revolution of Heavenly Spheres. What theory did Copernicus promote in this book, which was in conflict with the teachings of the Catholic Church?

A.
The Earth was not the center of the universe.
B.
Planets rotated on mini-orbits around the Earth.
C.
The Earth’s wobble on its axis produced seasonal changes.
D.
The center of the universe is far beyond the stars.

A. The Earth was not the center of the universe.