The pair of factors that affects the force of gravity between objects is distance and mass (option B).
Force of gravity is very long-range, but relatively weak fundamental force of attraction that acts between all particles that have mass. It is believed to be mediated by gravitons
In simpler words, force of gravity pulls objects with mass toward each other.
The force of gravity is dependent on the mass between objects and the distance between them.
Therefore, option B is correct.