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': 'Root planning is done to remove cementum that has been altered in conact with: \nSelect and explain. \nA. Exotoxins, B. Endotoxins, C. Granulation tissue, D. Junctional epithelial lining', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]