When an impulse reaches the end of a neuron, it triggers the release of

A. neurotransmitters.

B. sodium ions.

C. dendrites.

D. receptors.

The correct answer for the question that is being presented above is this one: "A. neurotransmitters." When an impulse reaches the end of a neuron, it triggers the release of neurotransmitters. The presynaptic cell releases neurotransmitters into the postsynaptic cell via the synaptic cleft. Neurotransmitters bind to receptor molecules in the postsynaptic cell, and are removed quickly by enzymes after the action potential is completed.