As per Coulomb's law of force we can say

here we can say
= magnitude of two charges
r = distance between two charges
so here we can say that force between two charges depends on
(i)product of charge of two point charges
(ii)distance between the two point charges
so here if we increase the distance force will decrease and vice versa.
So correct statement for the electrostatic force is given as
D. The electric force varies with the distance between the charges. The closer they are, the stronger the force. The farther apart they are, the weaker the force.