Answer:
The correct answer option is A. Acetylcholine.
Step-by-step explanation:
Acetylcholine is that neurotransmitter which stimulates the beginning of the muscle contraction and movement its movement.
The muscle tissues are composed of cells known as the muscle fibers. The nerve terminals present at the neuro muscular points releases a chemical message which is actually released by the motor neuron.
This neurotransmitter called acetylcholine binds itself to receptors on the outside of the muscle fiber which then causes muscle contraction and movement.