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: Gynaecology & Obstetrics
[{'content': "Alpha-fetoprotein is increased in following except: \nSelect and explain. \nA. Open neural tube defect, B. Down's syndrome, C. Oesophageal atresia, D. Exomphalos", 'role': 'user'}, {'content': "Answer: B \nExplanation: Down's syndrome", 'role': 'assistant'}]