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
Consolidation of which portion of the lung is likely to obliterate the Aortic knuckle on X–ray chest – 
Select and explain. 
A. Left Lingula, B. Right upper lobe, C. Apex of lower lobe, D. Left upper lobe (posterior part)
D: Left upper lobe (posterior part)
Answer: D: Left upper lobe (posterior part) 
Explanation: None