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
[{'content': 'Failure of closure of posterior neupore causes? \nSelect and explain. \nA. Anencephally, B. Spina bifida, C. Gastroschisis, D. Omphalocele', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Caudal or posterior neuropore closes by 28th day of intrauterine life Failure of closure leads to spina bifida', 'role': 'assistant'}]