At the Synapse,what Event Must Occur Before the Synaptic Vesicles

Multiple Choice

At the synapse,what event must occur before the synaptic vesicles release neurotransmitters?

A) The synaptic vesicles fuse with the presynaptic membrane.
B) The action potential causes voltage-gated channels to release calcium ions.
C) Neurotransmitters cross the synaptic cleft.
D) Neurotransmitters bind to postsynaptic receptors.
E) The neurotransmitters are inactivated by enzymes.