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': 'Variation of the eruption of the secondary dentition can be: \nSelect and explain. \nA. 5-8months., B. 4-5months., C. 12-18months., D. 8-9months', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Variation of eruption for primary dentition is 4-5 months.\nFor secondary dentition is12-18 months.', 'role': 'assistant'}]