This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
[{'content': 'Chest X-ray shows B/L lung infiltrates next investigation is \nSelect and explain. \nA. Sputum examination, B. Bronchospy, C. CT, D. Antibiotics', 'role': 'user'}, {'content': "Answer: C \nExplanation: In ARDS, a chest radiograph will show bilateral lung infiltrates. Chest CT scanning in ARDS reveals extensive heterogeneity of lung involvement. Chest X-ray in ARDS usually reveals opacities consistent with the pulmonary edema and often involves three-quaers of lung fields. But chest X-ray in ARDS does demonstrate pleural effusion, cardiomegaly, and pulmonary vascular distribution as seen in pure cardiogenic pulmonary edema. Reference: Harrison's Medicine, 20TH edition, page no:2032", 'role': 'assistant'}]