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': 'Periodontal pocket wall between tooth and bone is \nSelect and explain. \nA. Supra bony pocket, B. Intra bony pocket, C. Gingival pocket, D. Pseudo pocket', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]