Listed below are the events that make up chemical synaptic transmission.

1. Diffusion of transmitter across the synaptic cleft

2. Depolarization of the presynaptic terminal and release of calcium

3. Synaptic vesicle fusion with presynaptic membrane

4. Opening of voltage-gated ion channels

5. Binding of neurotransmitters to receptors

Which of the following is the correct sequence of these events?

a. 1; 2; 3; 4; 5

b. 2; 3; 1; 4; 5

c. 2; 3; 1; 5; 4

d. 5; 4; 2; 3; 1

e. 1; 2; 4; 5; 3