This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli), Subject name: Microbiology
[{'content': 'Organism most likely associated with VAP? \nSelect and explain. \nA. Pseudomonas, B. Klebsiella, C. Clostridium, D. Mycobacterium TB', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Gram negative bacilli are mostly responsible for ventilator associated pneumonia. Acinetobacter is most likely to cause ventilator associated pneumonia (VAP) since it is most commonly isolated during ICU sittings.', 'role': 'assistant'}]