Which statement best explains the relationship between the electric force between two charged objects and the distance between them?

a. as the distance increases by a factor, the electric force increases by the square of that factor.

b. as the distance increases by a factor, the electric force increases by twice that factor.

c. as the distance increases by a factor, the electric force decreases by twice that factor.

d. as the distance increases by a factor, the electric force decreases by the same factor.

e. as the distance increases by a factor, the electric force decreases by the square of that factor.