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': 'Gate system for pain control at \nSelect and explain. \nA. Substantia gelatinosa, B. Dorsal root ganglion, C. Both, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The gate for pain control is the enkephalinergic inhibitory interneurons situated in substatntia gelatinosa in dorsal horn of spinal cord.', 'role': 'assistant'}]