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
Birth weight doubles by? 
Select and explain. 
A. 3 months, B. 5 months, C. 9 months, D. 12 months
B: 5 months
Answer: B: 5 months 
Explanation: Ans. (b) 5 monthsRef O.P Ghai 8th ed/4Birth weight doubles at 5 months, triples in an year and is four times at 2 years and becomes 5 times at 3 years.Note: Newborns lose 10% of body weight in first ten days due to loss of extracellular water, after which they gain 25-30gms per day for first 3 months of life.