Final answer:
Pergolide (B) is the dopamine agonist among the given options. It is used to treat Parkinson's disease by mimicking the action of dopamine.
Step-by-step explanation:
Among the options given, Pergolide (B) is a dopamine agonist. Dopamine agonists are medications that mimic the action of dopamine, a type of neurotransmitter important for controlling the brain's reward and pleasure centers, as well as regulating movement and emotional responses. Pergolide is used in the treatment of Parkinson's disease, where it helps to address the deficiency of dopamine by binding to dopamine receptors and stimulating them. In contrast, Haloperidol (A) and Fluphenazine (E) are antipsychotic medications that act primarily as dopamine antagonists, blocking dopamine receptors, and Quetiapine (C) has a complex pharmacology with some dopamine blockade. Buspirone (D), while it affects serotonin receptors and can mildly influence dopamine receptors, is not classified as a dopamine agonist.