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': 'During growth cycle of a child, usually at what age childhood ends and adolescence stas? \nSelect and explain. \nA. 8 years, B. 10 years, C. 12 years, D. 16 years', 'role': 'user'}, {'content': 'Answer: B \nExplanation: WHO/UN definitions: Adolescent - 10-19 years Youth - 15-24 years Young people - 10-24 years Ref: Ghai essential pediatrics, 6th edition, Page 66.', 'role': 'assistant'}]