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: Ophthalmology
In a patient with AIDS, chorioretinitis is typically caused by – 
Select and explain. 
A. Cytomegalovirus, B. Toxoplasma gondii, C. Cryptococcus neoformans, D. Histoplasma capsulatum
A: Cytomegalovirus
Answer: A: Cytomegalovirus 
Explanation: The most common cause of chorioretinitis in AIDS is CMV.