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
Growth activity at which of these synchondroses completes first? 
Select and explain. 
A. Spheno-occipital, B. Intersphenoidal, C. Intra-occipital, D. Sphenoethmoidal
B: Intersphenoidal
Answer: B: Intersphenoidal 
Explanation: None