Answer:
Option (A).
Explanation:
Neuromuscular junction is formed by the connection between a muscle fiber and motor neuron. This is the site at which motor neuron transmit signal to the muscle fiber and causes muscle contraction.
Neuromuscular junction involves various critical events. The most important process that occur during muscular junction is the release of acetylcholine by the axon terminals of the motor neuron. Acetylcholine is a neurotransmitter and causes the stimulation of muscle tissue.
Thus, the correct answer is option (A).