When the charge inside the cell returns to the resting potential following depolarization, it is called:

Repolarization

Explanation:

Repolarization refers to the phase during which the resting potential is restored after depolarization. This means that the inside of the axon membrane becomes negative again compared to the outside.

Repolarization is obtained by the functioning of K+ ion channels. The opening of K+ ion channels allows the K+ to move outside of the axon. Movement of positively charged ion (K+) outside of axon makes the inside negative again and the resting potential is restored.