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': '28 weeks on USG-(TVS) a G2P1 female was detected as having major placenta pre. A confirm atoy scan should be performed: \nSelect and explain. \nA. At 32 weeks, B. At 34 weeks, C. At 36 weeks, D. At onset of labor', 'role': 'user'}, {'content': 'Answer: A \nExplanation: If the earlier scan showed a placenta completely over the internal os it is most likely to persist in later scans.If the 18-20 weeks scan revealed a lowlying placenta or a marginal placenta prae placental localization is best repeated around 32 weeks(refer pgno:130 sheila textbook of obstetrics 2 nd edition)', 'role': 'assistant'}]