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 fetal blood is separated from syncytiotrophoblast with all the following except \nSelect and explain. \nA. Fetal blood capillary membrane, B. Mesenchyme of intervillous blood space, C. Cytotrophoblast, D. Decidua parietalis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The decidua over the abembryonic pole is the decidua capsularis. \nThe chorionic cavity becomes larger. the decidua capsularis is stretched and degenerates.\nThe chorion leave now comes into close contact with the uterine wall on the opposite side, resulting in the formation of the decidua parietalis.', 'role': 'assistant'}]