Repolarization occurs because __________.

A  more sodium ions diffuse into the cell than potassium ions diffuse out of it

B  potassium ions continue to diffuse out of the cell after the inactivation gates of the voltage-gated sodium ion channels begin to close

C  the inactivation gates of the voltage-gated sodium ion channels begin to open and the diffusion of sodium ions decreases

D  the extra efflux of potassium ions causes the membrane potential to become slightly more positive than the resting value

E  the increased potassium ion permeability lasts slightly longer than the time required to bring the membrane potential back to its resting level