the life cycle. the water cycle. the solar system. the immune system.
I gave my students this multiple choice question: The Heliocentric Theory, as supported by Copernicus, revolutionized scientific theories regarding

Only one answer is correct among these 4 choices:
- the life cycle.
- the water cycle.
- the solar system.
- the immune system.

Could you tell me which one is correct?

the solar system.