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: Surgery
Which of the following route of infection is most responsible for lung abscess? 
Select and explain. 
A. Direct inoculation, B. Inhalation of infection, C. Spread from adjacent side of infection, D. Aspiration of organisms from Oropharynx
D: Aspiration of organisms from Oropharynx
Answer: D: Aspiration of organisms from Oropharynx 
Explanation: Aspiration of organisms present in oropharynx is the most common route of infection, which classically leads to anerobic lung abscess.