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: Dental
First growth spurt takes place at what age 
Select and explain. 
A. 1st year, B. 3rd year, C. 6th year, D. 9th year
A: 1st year
Answer: A: 1st year 
Explanation: None