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': 'Opportunistic lung infection in AIDS is due to- \nSelect and explain. \nA. Pneumocystis carini, B. Klebsiella, C. Mucormycosis, D. Mycoplasma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]