A)synaptic vesicles fuse with the postsynaptic membrane. B)synaptic vesicles fuse with the pre-synaptic membrane. C)neurotransmitters diffuse across the synaptic cleft. D)neurotransmitters are actively transported across the synaptic cleft. E)synaptic vesicles fuse with the pre-synaptic membrane and neurotransmitters diffuse across the synaptic cleft.