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: Pathology
[{'content': 'Easy muscle fatigability is a feature of: \nSelect and explain. \nA. Facial palsy., B. Myasthenia gravis., C. MPDS., D. All of the above.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]