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': 'Cause of blindness in CRVO \nSelect and explain. \nA. Cystoid macular edema, B. Macular hemorrhage, C. Vitreous hemorrhage, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: All are causes of blindness in CRVO but most important is CME.', 'role': 'assistant'}]