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': 'Pricking pain, cold , crude touch is conducted by \nSelect and explain. \nA. A alpha, B. A beta, C. A gamma, D. A delta', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]