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 age by which most of the normal babies know their gender is - 
Select and explain. 
A. 1 year, B. 2 years, C. 3 years, D. 4 years
C: 3 years
Answer: C: 3 years 
Explanation: Ans. is 'c' i.e., 3 years