What Ensures the One-Way Direction of an Action Potential

Multiple Choice

What ensures the one-way direction of an action potential?

A) As soon as the action potential has passed by, that portion of the axon undergoes a short refractory period.
B) Action potentials are self-propagating.
C) Conduction of an action potential is an all-or-none event.
D) An action potential at one node causes an action potential at the next node.
E) An axon can conduct a volley of action potentials very quickly.