This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Medicine
Most com mon cause of lu ng abscess ? 
Select and explain. 
A. Staph aureus, B. Oral anaerobes, C. Klebsiella, D. Tuberculosis
B: Oral anaerobes
Answer: B: Oral anaerobes 
Explanation: Ans. is 'b' i.e., Oral Anaerobes o According to Harrison# Most nonspecific lung abscesses are presumed to be due to anaerobic bacteria.