1. Which combination of charge and distance would lead to the strongest repulsive force ?

A. a + 1 charge and a -1 charge at a distance of 1.5 meters

B. a + 3 charge and a + 3 charge at a distance of 0.5 meters

C. a + 4 charge and a - 4 charge at a distance of 0.5 meters

D. a + 2 charge and a + 2 charge at a distance of 1.5 meters

C. a + 4 charge and a - 4 charge at a distance of 0.5 meters

This combination would lead to the strongest repulsive force because the charges are the highest and the distance between them is the smallest.