Which change increases the electric force between objects?
a) two neutral objects are moved closer together.
b) electrons are added to two negatively charged objects.
c) two oppositely charged objects are moved farther apart.
d) the charge on two positively charged objects is reduced.

By definition we have that the electric force is given by:

Where,

k: proportionality constant

q1: electric charge of object 1

q2: electric charge of object 2

d: distance between both objects

Therefore, to increase the electric power there are two possible cases:

1) Add more load to each object

2) Decrease the distance between objects.

The option that increases the electric force for this case is:

Electrons are added to two negatively charged objects.

This is because the values of q1 and q2 increase.

A change that increases the electric force between objects is:

B) Electrons are added to two negatively charged objects.

hey , the answer is c