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: Pathology
[{'content': 'All are obstructive lung disease except \nSelect and explain. \nA. Emphysema, B. Interstitial fibrosis, C. Asthma, D. Bronchitis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]