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': 'Postganglionic fibers are: \nSelect and explain. \nA. Type c fibers, B. Type B fibers, C. Both, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Postganglionic fibers are type C fibers They are non myelinated, they have slow conduction velocity Ref:Guyton and Hall textbook of medical physiology 12th edition,page number: 73', 'role': 'assistant'}]