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: Pediatrics
[{'content': 'At what age upper segment  : Lower segment ratio becomes 1 : 1? \nSelect and explain. \nA. 3-6 years, B. 5-8 years, C. 7-10 years, D. 10-12 years', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Age\nUS : LS ratio\n\n\n\n\nBirth\n\t\t\t3 years\n\t\t\t7-10 years\n\t\t\t> 10 years\n1.7 : 1\n\t\t\t1.3 : 1\n\t\t\t1 : 1\n\t\t\t0.9 : 1', 'role': 'assistant'}]