This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Assessment of Growth, Subject name: Pediatrics
Definition of childhood is under what age? 
Select and explain. 
A. 8 years, B. 10 years, C. 12 years, D. 16 years
C: 12 years
Answer: C: 12 years 
Explanation: ANSWER: (C) 12 yearsREF: Nelson Textbook of Paediatrics 17th edition different pagesInfancy0-1 yrToddlerhood1-3 yrEarly childhood (toddlerhood and some time afterwards)1-4 yrMiddle Childhood (School Age)6-12 yrPreschool2-5 yrAdolescence (onset of puberty to maturity)12-20 yrAdulthood (full physical and intellectual maturity)20-21 yr onwards