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
Opportunistic lung infection in AIDS is due to- 
Select and explain. 
A. Pneumocystis carini, B. Klebsiella, C. Mucormycosis, D. Mycoplasma
A: Pneumocystis carini
Answer: A: Pneumocystis carini 
Explanation: None