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': 'Cephalization of pulmonary blood vessels is seen in all except \nSelect and explain. \nA. Aortic stenosis, B. Mitral stenosis, C. Severe mitral regurgitation, D. Severe aortic  regurgitation', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Cephalization of pulmonary vessels\xa0 seen on radiography is the earliest sign of pulmonary venous hypertension.\xa0 Usually occurs in left sided obstructive lesions,\xa0 L.V failure.', 'role': 'assistant'}]