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': 'A positive "Stallwohy&;s sign" is suggestive of which of the following conditions: \nSelect and explain. \nA. Twin pregnancy, B. Breech presentation, C. Vesicular mole, D. Low lying placenta', 'role': 'user'}, {'content': 'Answer: D \nExplanation: If the earlier scan showed placenta completely over the internal os it is most likely to persist in the later scans.If the 18 -20 weeks scan revealed a low lying placenta or marginal placenta prae,placental localization is best repeated around 32 weeks (refer pgno:130 sheila textbook of obstetrics 2 nd edition)', 'role': 'assistant'}]