This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Physiology of Pain, Subject name: Physiology
[{'content': 'Fast pain has a conduction velocity of _____ m/sec. \nSelect and explain. \nA. 1, B. 5, C. 15, D. 50', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Fast pain has a nerve fiber (A delta) conduction velocity of 12 to 30 m/sec. Slow pain has a nerve fiber (C) conduction velocity of 0.5 to 2 m/sec.', 'role': 'assistant'}]