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': "American society of anesthesiologists' physical status classification system, P2 is a is a patient who \nSelect and explain. \nA. Is healthy, B. With mild systemic disease, C. With severe systemic disease, D. None of the above", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]