The Accompanying Figure Relates to Events at the Neuromuscular Junction

Multiple Choice

The accompanying figure relates to events at the neuromuscular junction. Match the steps highlighted in the figure (steps 1-9) with the statements using the letter key below.
-action potential triggers opening of voltage-gated calcium channels in motor neuron axon terminal

A) Step 1
B) Step 2
C) Step 3
D) Step 4
E) Step 5
F) Step 6
G) Step 7
H) Step 8
I) Step 9