(Need it to be 100% correct please) Which provides the best summary of the following paragraph?

"After spending countless hours observing the planets and stars, Copernicus issued a startling new theory about how the solar system works. In opposition to the previous model, which held that the Sun and other planets orbited around the Earth, Copernicus stated that the Earth is just one of many planets that orbit around the Sun."

a. Copernicus posited that the Earth and other planets orbit around the Sun, instead of other solar bodies orbiting around the Earth.

b. Copernicus created a new system to explain how objects orbit and move in outer space.

c. Copernicus spent a lot of time studying the planets and stars before announcing his new theory.