This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal tract, Subject name: Pharmacology
[{'content': 'Which of following drugs is not an antiemetic? \nSelect and explain. \nA. Ondansetron, B. Domperidone, C. Metaclopromide, D. Cinnarizine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Cinnarizine is an anti veigo drug. Metaclopromide 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'}]