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: Medicine
[{'content': 'Barrel chest is usually associated with: \nSelect and explain. \nA. Chronic bronchitis, B. Left heart failure, C. Anasarca, D. Perforated lung', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]