What event causes the membrane potential to drive back down toward the resting level during repolarization?

Answer

Slow opening of voltage-gated $ ext{K}^+$ channels leading to $ ext{K}^+$ efflux

As the membrane depolarizes, voltage-gated potassium channels open slowly. The subsequent efflux of positive potassium ions drives the membrane potential back toward the negative resting level.

What event causes the membrane potential to drive back down toward the resting level during repolarization?
membraneaction potentialneuronion channelelectrical signal