Which one of the following is the correct sequence of events that follows in a synaptic transmission of nerve impulse?

1. The presynaptic membrane is depolarized.
2. Voltage gated calcium channels open
3. Release of synaptic Vesicles
4. Calcium enters the synaptic knob
5. The neurotransmitter diffuses across the synaptic cleft and binds to the receptor proteins on the postsynaptic membrane.