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: Dental
[{'content': "Intrabony pockets are given a score of ___________ in\nRussell's periodontal index: \nSelect and explain. \nA. 3, B. 4, C. 6, D. 8", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]