The correct answer is to break down acetylcholine.
Acetylcholine esterase is an enzyme found in the synaptic clefts of the nervous system and it functions to terminate the action of acetylcholine by breaking it down to acetyl-CoA and choline, rendering the neurotransmitter functionless. Choline and acetyl-CoA will then go back to the presynaptic neuron by reuptake and acetylcholine will be formed again inside the neuron.