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': 'The most likely diagnosis in a 25 year old male having generalized restriction of eye movement in all direction, intermittent ptosis, proximal muscle weakness, fatiguability. The most useful test is: \nSelect and explain. \nA. CPK, B. Edrophoneium test, C. EMG, D. Muscle biopsy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Edrophoneium test', 'role': 'assistant'}]