Answer :
Answer:
c. synaptic cleft
Explanation:
A neuromuscular junction is formed between a motor neuron and a muscle fiber called as sarcolemma. A signal is passed from motor neuron to muscle fiber which eventually leads to muscle contraction.
Motor neurons release the neurotransmitter Acetylcholine in synaptic cleft. Acetylcholine diffuses through it and ultimately binds to the nicotinic acetylcholine receptors on cell membrane of sarcolemma. Nicotinic acetylcholine receptors are ligand gated ion channels and get depolarized by binding to acetylcholine which results in muscle contraction.