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': 'The main bulk of dentin is formed by \nSelect and explain. \nA. Peritubular dentin, B. Mantle dentin, C. Inter tubular dentin, D. Predentin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]