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
Closure of Neural tube begins at which of the following level? 
Select and explain. 
A. Cervical region, B. Thoracic region, C. Cephalic end, D. Caudal end
B: Thoracic region
Answer: B: Thoracic region 
Explanation: Fusion of neural folds begins in middle and gradually extend in cranial and caudal directions REFERENCE: TEXTBOOK OF CLINICAL EMBRYOLOGY... VISHRAM SINGH SECOND EDITION..PAGE NO:52