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': 'The main motor supply of intrafusal fibers is \nSelect and explain. \nA. Gamma neurons, B. Alpha neurons, C. Beta neurons, D. All of the following', 'role': 'user'}, {'content': 'Answer: A \nExplanation: MOTOR NERVE FIBERS', 'role': 'assistant'}]