Generally, Nerve Impulses Do Not Move "Backward" Along a Series

Multiple Choice

Generally, nerve impulses do not move "backward" along a series of neurons. What is the reason for this?

A) There is a short refractory period during which sodium gates cannot open and an action potential cannot move backwards.
B) Once the signal has passed, the nerves separate from each other so it cannot go backwards.
C) At the synapse, the presynaptic membrane has receptors, ensuring the transmission only goes one way.
D) Once the sodium channels open, they cannot be closed.
E) The resting potential of the neuron prevents it from conducting an impulse.