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': 'The earliest and most conclusive sign of intrauterine fetal death is / sure sign of IUD is: \nSelect and explain. \nA. Spalding sign, B. Intrafetal gas in areas of great vessels and hea, C. Crowding of ribs, D. Hyperflexion of spine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Intrafetal gas in areas of great vessels and hea', 'role': 'assistant'}]