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
[{'content': 'The commonest ocular infection associated with AIDS is: \nSelect and explain. \nA. Herpes zoster, B. Ctomegaloviruys, C. Toxoplasmosis, D. Tuberculosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans Ctomegaloviruys', 'role': 'assistant'}]