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': 'Which of the following types of nerve fibres carry fast pain: \nSelect and explain. \nA. A alpha, B. A beta, C. A gamma, D. A delta', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A delta', 'role': 'assistant'}]