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: Medicine
[{'content': 'In cystic fibrosis, pseudomonas aeroginosa is most common arganism. The next most common is \nSelect and explain. \nA. Steptococci, B. Klebsiella, C. Pnuemococci, D. Staphylococcus aureus', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]