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: Microbiology
Which of the following pneumonia is caused by contaminated air conditioner: 
Select and explain. 
A. Pneumococci, B. Staphylococci, C. E. coli, D. Legionella
D: Legionella
Answer: D: Legionella 
Explanation: Ans. is. 'd' i. e., Legionella