Gravitational force between two objects depends on the mass of each object and the distance between the object. this makes the correct answer: D (Both B and C). We can conclude this from the Newton's equation:
E(grav) (proportional to) m1*m2/d^2,
where E is the force of gravitational attraction, m1 and m2 are the masses of the objects and d is the distance that separates their centers.
