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': 'Adolescent starts at the age of ? \nSelect and explain. \nA. 7 years, B. 10 years, C. 14 years, D. 17 years', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]