Answer:E) Voltage-gated calcium channels open
F) Calcium enters the synaptic knob
G) Synaptic vesicles merge with synaptic knob plasma membrane
H) Neurotransmitter is released by exocytosis
B) Neurotransmitter attaches to receptors on a muscle, neuron, or gland cell
I) Action potential reaches synaptic knob
Explanation: