This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Adolescence, Subject name: Pediatrics
WHO defines adolescent age group as 
Select and explain. 
A. 14-21 years, B. 13-20 years, C. 10-19 years, D. 10-17 years
C: 10-19 years
Answer: C: 10-19 years 
Explanation: The World Health Organization (WHO) defines an adolescent as any person between ages 10 and 19.