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\n1.7 : 1\n\n\n3 years\n1.3 : 1\n\n\n7 - 10 years\n1 : 1\n\n\n> 10 years\n0.3 : 1', 'role': 'assistant'}]