The Main Difference Between Autoreceptors and Heteroreceptors Is That

The main difference between autoreceptors and heteroreceptors is that

A) heteroreceptors are activated by a different neuron and neurotransmitter, whereas autoreceptors are activated by the neuron they regulate.
B) heteroreceptors are postsynaptic, whereas autoreceptors are presynaptic.
C) heteroreceptors are metabotropic, whereas autoreceptors are ionotropic.
D) heteroreceptors are excitatory, whereas autoreceptors are inhibitory.