At the Peak of an Action Potential

Multiple Choice

At the peak of an action potential:

A) The electrical gradient for Na⁺ causes a net movement of this ion out of the cell.
B) The concentration gradient for K⁺ tends to move this ion out of the cell.
C) K⁺ permeability greatly increases.
D) All of these.
E) The concentration gradient for K⁺ tends to move this ion out of the cell, and K⁺ permeability greatly increases.