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': 'Accurate diagnosis of anencephaly in ultrasound is seen at week : \nSelect and explain. \nA. 6 weeks of gestation, B. 8 weeks of gestation, C. 10 weeks of gestation, D. 14 weeks of gestation', 'role': 'user'}, {'content': 'Answer: D \nExplanation: 14 weeks of gestation', 'role': 'assistant'}]