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: Pathology
[{'content': 'Which of the following is not a type of dental caries based on senility of dental caries: \nSelect and explain. \nA. Rampant caries., B. Arrested caries., C. Recurrent caries., D. None.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Based on whether it is new or occurring at margin of restoration\n\nPrimary\nRecurrent (Secondary)\n\nBased on senility of dental caries\n\nRampant\nArrested', 'role': 'assistant'}]