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': 'Which of the following is true about multiple sclerosis except - \nSelect and explain. \nA. Nystagmus on abducting eye, B. Nystagmus on adducting eye, C. One and half syndrome, D. Pendular nystagmus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]