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 are unmyelinated nerve fibers? \nSelect and explain. \nA. Proprioceptive fibers, B. Motor neuron to muscle, C. Postganglionic sympathetic fibers, D. Motor nerve to intrafusal fibers', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Postganglionic sympathetic fibers[Ref Ganong 24h/e p. 92; Principles of medical physiology p. 5I2lType C fibers are unmyelinated fibers which include postganglionic autonomic fibers,", 'role': 'assistant'}]