This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Gynae), Subject name: Gynaecology & Obstetrics
[{'content': 'Which will not come between cytotrophoblast and maternal blood? \nSelect and explain. \nA. Decidua parietalis, B. Syncytiotrophoblast, C. Inter villous space, D. Basement membrane', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans: a (Decidua parietalis) Ref: Dutta, 6th ed, 31As seen clearly from the diagram, the decidua parietalis is situated away from the attatchment of the embryo and thus cannot come between the maternal blood and cytotrophoblast.', 'role': 'assistant'}]