Ligand-Gated Ion Channels Are Found Within the Postsynaptic Neuron's Cell

Ligand-gated ion channels are found within the postsynaptic neuron's cell membrane. Why are ligand-gated ion channels critical to how synapses communicate information?

A) Ligand-gated ion channels enable specific neurotransmitters released by presynaptic neurons to exert either excitatory or inhibitory effects on the postsynaptic cell.
B) Ligand-gated ion channels open more rapidly than voltage-gated ion channels.
C) Ligand-gated ion channels allow the postsynaptic cell to control, through intracellular signaling, to which neurotransmitters the postsynaptic cell responds.
D) Ligand-gated ion channels are found within a neuron's dendrites but not its axon.