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 receptor is responsible for monitoring the rate of muscle stretch? \nSelect and explain. \nA. Nuclear bag intrafusal fibers, B. Nuclear chain, C. Golgi tendon organ, D. Pacinium corpuscles', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]