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': 'Consolidation of which portion of the lung is likely to obliterate the Aortic knuckle on X–ray chest – \nSelect and explain. \nA. Left Lingula, B. Right upper lobe, C. Apex of lower lobe, D. Left upper lobe (posterior part)', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]