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': 'Definition of Prolonged pregnancy is \nSelect and explain. \nA. Completed 38weeks, B. Completed 40weeks, C. Completed 41weeks, D. Completed 42weeks', 'role': 'user'}, {'content': "Answer: D \nExplanation: The international definition of prolonged pregnancy, endorsed by the American College of Obstetricians and Gynecologists (2013a), is 42 completed weeks, 294 days or more from the first day of the last menstrual period.Reference: William's Obstetrics; 24th edition; Chapter 43; Postterm Pregnancy", 'role': 'assistant'}]