Answer:
a. the force between them quadruples
Step-by-step explanation:
The electrostatic force between two charges is given by
where
k is the Coulomb's constant
q1 and q2 are the two charges
r is the separation between the two charges
In this problem, the charges on both objects are doubled, so
While the distance does not change, so the new force will be
so, the force will quadruple.