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
Closure of the anterior fontanelle is delayed in all except – 
Select and explain. 
A. Down's syndrome, B. Osteogenesis imperfecta, C. Hypogonadism, D. Hypothyroidism
C: Hypogonadism
Answer: C: Hypogonadism 
Explanation: Delayed closure of anterior fontanel / wide (large) anterior fontanel

The anterior fontanel nonnally closes between 12 to 18 months of age.
The presence of excessively large anterior fontanel and its delayed closure is a recognised clinical feature in following conditions.