This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Most important receptor involved in chemotherapy induced vomiting is : \nSelect and explain. \nA. Histamine H1 receptor, B. Serotonin 5–HT3 receptor, C. Dopamine D2 receptor, D. Opioid µ receptor', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]