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 Thirty five year old female has proximal weakness of muscles, ptosis and easy fatigability. The most sensitive test to suggest the diagnosis is - \nSelect and explain. \nA. Muscle Biopsy, B. CPK levels, C. Edrophonium test, D. Single fiber EMG', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]