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': 'Percentage of inorganic component in cementum is: \nSelect and explain. \nA. 30%, B. 40-50%, C. 50-55%, D. 20-30%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]