All of These Contribute to the Cessation of the Signal

All of these contribute to the cessation of the signal in a synaptic transmission except

A) synaptic vesicles secrete neurotransmitter by exocytosis.
B) neurotransmitter escapes from the synapse into the nearby extracellular fluid.
C) neurotransmitters stop being released.
D) the synaptic knob reabsorbs some neurotransmitters by endocytosis.
E) enzymes in the postsynaptic cell break down some neurotransmitters.