Tricyclic Antidepressant Drugs Are So Named Because of the ________

Tricyclic antidepressant drugs are so named because of the ________.

A) three cycles of metabolism that they undergo before being excreted
B) three hormones (dopamine, serotonin, and acetylcholine) that are affected by these drugs
C) triple action of these drugs in the limbic system, motor cortex, and hypothalamus in the brain
D) triple-ring configuration of the chemical structure of the drug