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': 'Ataxia, nystagmus and ophthalmoplegia is seen in - \nSelect and explain. \nA. Mysthenia gravis, B. Chronic progressive external ophthalmoplegia, C. 3\nrd\n nerve palsy, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]