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
Most common organism causing ventilator associated pneumonia - 
Select and explain. 
A. Legionella, B. Pneumococcus, C. Pseudomonas, D. Coagulase negative staphylococcus
C: Pseudomonas
Answer: C: Pseudomonas 
Explanation: None