This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Average head circumference at bih is ? 
Select and explain. 
A. 35 cm, B. 40 cm, C. 45 cm, D. 50 cm
A: 35 cm
Answer: A: 35 cm 
Explanation: O.P. Ghai 9th ed, page 14 Beginning at 34 cm at bih, the head circumference increases approximately 2 cm per month for first 3 months, 1 cm per month from 3-6 months and 0.5 cm per month for rhe rest of the first year of life.