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
Commonest site of lung abcess is- 
Select and explain. 
A. Post segment of right upper lobe, B. Lingula, C. Post segment of left lower lobe, D. Post segment of right lower lobe
A: Post segment of right upper lobe
Answer: A: Post segment of right upper lobe 
Explanation: None