This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
[{'content': 'The diameter of Type C fibers is \nSelect and explain. \nA. 13-20mm, B. 4-13mm, C. 3-6mm, D. 0.5-2mm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Unmyelinated fibers carrying pain, itch, temperature, and crude touch sensations (0.5 to 2 micrometers in diameter; they are type C fibers in the generalclassification).Ref: Guyton; 13th edition; Chapter 47 Sensory Receptors, Neuronal Circuits for Processing Information', 'role': 'assistant'}]