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: Unknown
Which of the fontalle is the last to close after birth 
Select and explain. 
A. Anterior fontanelle, B. Posterior fontanelle, C. Sphenoidal fontanelle, D. Mastoid fontanelle
A: Anterior fontanelle
Answer: A: Anterior fontanelle 
Explanation: Ref. The Short Textbook of Pediatrics. Pg 550
 

Anterior fontanelle closes  around 10-18 months
Posterior fontanelle closes around 8 weeks
Persistent posterior fontanelles is earliest sign of hypothyroidism