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
Birth weight of newborn baby doubles by ? 
Select and explain. 
A. 4 months, B. 5 months, C. 6 months, D. 7 months
B: 5 months
Answer: B: 5 months 
Explanation: Birth weight doubles by 5 months,
triples by 1  year,
Quadruples by 2  years.