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
90% of brain growth is achieved by the – 
Select and explain. 
A. 2nd year, B. 3rd year, C. 5th year, D. 15th year
A: 2nd year
Answer: A: 2nd year 
Explanation: The brain enlarges rapidly during the latter months of fetal life and early months of postnatal life.
At birth, the head size is about 65 to 70 percent of the expected head size in adults.
It reaches 90 percent of the adult head size by the age of 2 years.