This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Misc., Subject name: Microbiology
[{'content': 'Most common cause of pneumonia in AIDS patients \nSelect and explain. \nA. Pneumococci, B. Staphylococci, C. Pneumocystis carni, D. All of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: (C) Pneumocystis carnii > Pneumocystis carini is most common cause of pneumonia in AIDS.', 'role': 'assistant'}]