Answer:
D
Explanation:
During action potential, sodium channels which is an integral membrane protein that regulates the sodium ion opens first and more quickly than the potassium channel thereby allowing increased influx of sodium ion as sodium ion rushes into the cell.
This influx changes the electrochemical gradient, with a resultant further rise in the membrane potential of the cell producing a greater electric current across the cell membrane. This Voltage-activation then causes Potassium channels to open.
