Answer:
Both distance between and mass of the 2 objects
Explanation:
The gravitational pull between two objects is given by:

where
G is the gravitational constant
m1 is the mass of the first object
m2 is the mass of the second object
r is the distance between the two objects
From the formula, we see that the gravitational pull depends both on the distance between the two objects (r) and on their masses (m1, m2), so the correct answer is
Both distance between and mass of the 2 objects