This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pneumonia, Subject name: Medicine
Which of the following is used for the prevention of Pneumocystis jiroveci infection in HIV positive patients? 
Select and explain. 
A. Azithromycin, B. Acyclovir, C. Levofloxacin, D. Sulfamethoxazole + trimethoprim
D: Sulfamethoxazole + trimethoprim
Answer: D: Sulfamethoxazole + trimethoprim 
Explanation: Prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMZ) prevents- infection with P.Jiroveci, Toxoplasma gondii. Intolerance of TMP-SMZ is common Alternative agents provide less adequate protection against Pneumocystis species.