This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Retina, Subject name: Ophthalmology
[{'content': 'Diagnosis of CMV retinitis is primarily by? \nSelect and explain. \nA. Fundoscopy, B. Retinal biopsy, C. CMVDNA, D. ELISA', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) FundoscopyRef: Kanski 7/e, chapter 11, Intraocular drug delivery by glenn J. Jaffe p 330', 'role': 'assistant'}]