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': "'S' shape of dentinal tubule is due to: \nSelect and explain. \nA. Incremental deposition, B. Peritubular dentin, C. Crowding of odontoblasts, D. Due to excess amount of organic component", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]