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 nerve fibres has the highest conduction velocity? \nSelect and explain. \nA. Aα, B. Aβ, C. Aγ, D. B', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Types of mammalian nerve fibers:', 'role': 'assistant'}]