Respuesta :
The correct option is C.nitric oxide.
Acetylcholine is a key neurotransmitter in nerves and muscles especially neuromuscular junction( which connects nerves to muscles). When an action potential reaches a pre-synaptic membrane this neurotransmitter is released.
Acetylcholine then binds to the receptor on the postsynaptic membrane. The receptor proteins are of two types. First is ligand-activated ion channels. These receptors are membrane-spanning ion channel proteins that open directly in response to ligand binding.
The second is metabotropic channels. These receptors are not themselves ion channels. Neurotransmitter binding triggers a signalling pathway, which may indirectly open or close channels (or have some other effect entirely)
Learn more about nitric oxide here: https://brainly.com/question/14580140
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