The Primary Reason Why Neurons Are Refractory for a Short

Multiple Choice

The primary reason why neurons are refractory for a short period after firing action potentials, and the reason underlying the absolute refractory period, is that the

A) voltage-gated sodium channels are inactivated.
B) voltage-gated potassium channels are inactivated.
C) sodium-potassium pump has to remove sodium ions from inside the cell.
D) sodium-potassium pump has to retrieve potassium ions from outside the cell.