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: Physiology
[{'content': 'The following electrodes are used to detect the muscle activity without pain: \nSelect and explain. \nA. Surface electrode, B. Round electrode, C. Hook electrode, D. Needle electrode', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]