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: Radiology
[{'content': 'Hilar markings in a normal chest X-ray is formed by all except: \nSelect and explain. \nA. Pulmonary aery, B. Bronchi, C. Upper lobe veins, D. Upper lobe veins', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Upper lobe veins', 'role': 'assistant'}]