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': 'Organic content of Dentin is \nSelect and explain. \nA. 15%, B. 35%, C. 65%, D. 5%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Dentin forms bulk of the tooth tissues and occupies both the crown and the root. It is surrounded by the enamel in the crown and cementum in the root. Physically and chemically it resembles bone. Dentin consists of 65% inorganic and 35% organic material. The organic substance consists mainly of type I collagen fibers embedded in ground substance of mucopolysaccharides. The inorganic component consists of plate shaped hydroxyapatite crystals.', 'role': 'assistant'}]