Which of the Following Is the Last Step for Synaptic

Multiple Choice

Which of the following is the last step for synaptic signalling when the action potential arrives at the axon terminal of a presynaptic neuron

A) A neurotransmitter is released by exocytosis.
B) Calcium flows in the synaptic knob.
C) The neurotransmitter combines with protein receptor sites on the subsynaptic membrane.
D) The permeability is altered in a postsynaptic neuron.