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': 'A women has had 2 previous anencephalic babies, risk of having a third one is: \nSelect and explain. \nA. 0%, B. 10%, C. 25%, D. 50%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The risk of recurrence of anencephaly:\nIf one child is affected 5%\nIf two children are affected 13%', 'role': 'assistant'}]