This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-Emetic, Subject name: Pharmacology
[{'content': 'Which of the following drugs is not an antiemetic? \nSelect and explain. \nA. Ondansetron, B. Domperidone, C. Metoclopramide, D. Cinnarizine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. (D) Cinnarizine(Ref: KDT, 18th/e p712)Cinnarizine is an anti-vertigo drug.Metoclopramide and domperidone are antiemetic drugs. These act by blocking D2 receptors.Ondansetron is an antagonist of 5HT3 receptors. It is the drug of choice for chemotherapy induced vomiting.', 'role': 'assistant'}]