After the action potential reaches its peak, the potential across the membrane falls toward its resting level. What accounts for this recovery? A. The sodium–potassium pump removes the extra sodium....

After the action potential reaches its peak, the potential across the membrane falls toward its resting level. What accounts
for this recovery?
A. The sodium–potassium pump removes the extra sodium.
B. Sodium ions move out because their channels are open and the concentration gradient pushes them out.
C. Potassium ions move out because their channels are open and the concentration gradient pushes them out.
D. Potassium ions move in.