their masses, only their diameters, only their masses and how far apart they are their diameters and how far apart they are
I gave my students this multiple choice question: The gravitational force between the Moon and Earth depends on

Only one answer is correct among these 4 choices:
- their masses, only
- their diameters, only
- their masses and how far apart they are
- their diameters and how far apart they are

Could you tell me which one is correct?

their masses and how far apart they are