What Key Aspect of a Depressant's Chemical Action Sets It

What key aspect of a depressant's chemical action sets it apart from the other classes of psychoactive drugs?

A) Depressants are active along the whole length of the neuron.
B) Depressants are only active at the synaptic cleft.
C) Depressants are irreversibly bound to neuron surface proteins.
D) Depressants are involved in the degradation of neurotransmitters.
E) none of the above