The Absolute Refractory Period

The absolute refractory period

A) prevents action potentials from spreading forward and backward
B) refers to a period when the membrane cannot undergo another action potential
C) is the time when channels opened during the action potential have not been restored to their "closed but capable of opening" conformation
D) places an upper limit on the frequency with which a neuron can conduct action potentials
E) refers to a period when the membrane cannot undergo another action potential and places an upper limit on the frequency with which a neuron can conduct action potentials