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': 'Chest X-ray shows B/L lung infiltrates next investigation is - \nSelect and explain. \nA. Sputum examination, B. CT, C. Bronchoscopy, D. Antibiotics', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]