Adrug that blocks the action of the neurotransmitter is called

A drug that blocks the action of the neurotransmitter is called antagonist.
These drugs block the action of the neurotransmitter by occupying their receptor sites and the drug that does not block the action and have an affect on the neurotransmitter are known as agonist. A chemical messengers to activate or enable neurotransmission are known as neurotransmitters.

The answer is c : ) hope this answered your question!