The correct answer is: B) developing a heliocentric theory.
Explanation:
Nicolaus Copernicus was a Prussian monk, mathematician and astronomer from the Renaissance era famous for coming up with the heliocentric theory.
<u>The heliocentric theory proposes that the Sun is in the center of our system and the Earth and the other planets revolve around it.</u> Before this theory, it was believed that the Sun revolved around the Earth (geocentrism).