This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
[{'content': 'Which of the following nerve fibre is unmylenated? \nSelect and explain. \nA. A-aplha, B. A-beta, C. A-delta, D. C fiber', 'role': 'user'}, {'content': 'Answer: D \nExplanation: C fibres are unmyelinated fibres and they are the slowest ones to conduct an impulse.Ref: Ganong&;s review of medical physiology; 23rd edition; pg:88', 'role': 'assistant'}]