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: Medicine
[{'content': 'A 9 years old Raju develops sudden loss of vision in both eyes. following an attack of measles. The probate cause is - \nSelect and explain. \nA. B/L optic neuritis, B. Encephalitis, C. Keratonealacia, D. Raised intraocdura pressure', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]