How Do Neurotransmitters "Communicate" with Postsynaptic Neurons

Multiple Choice

How do neurotransmitters "communicate" with postsynaptic neurons?

A) Like a "key fitting into a lock," they bind with corresponding receptor sites on dendrites of the neuron.
B) Like "water over a dam," they build up until they flood into the next neuron through sheer force.
C) Like a "hot knife through butter," they easily penetrate right into the cell body through the dendrites.
D) Like "throwing darts," they are propelled across the synapse and communicate with the neuron wherever they land.