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
The height of a child is double the birth height at the age of – 
Select and explain. 
A. 1 year, B. 2 years, C. 4 years, D. 6 years
C: 4 years
Answer: C: 4 years 
Explanation: An infant usually doubles his birth height by the age of 41/2 years