This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': 'Prolonged pregnancy is the one that exceeds \nSelect and explain. \nA. 390/7, B. 400/7, C. 410/7, D. 420/7', 'role': 'user'}, {'content': "Answer: D \nExplanation: The international definition of prolonged pregnancy, endorsed by the American College of Obstetricians and Gynecologists (2016b,d) is one that exceeds 420/7 weeks, namely, 294 days or more from the first day of the last menstrual period.Reference: William's Obstetrics; 25th edition; Chapter 43; Postterm pregnancy", 'role': 'assistant'}]