This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Placenta and Chorion Development, Subject name: Gynaecology & Obstetrics
[{'content': 'True about circumvallate placenta is? \nSelect and explain. \nA. Fetal plate smaller than basal plate, B. Basal plate smaller than fetal plate, C. Has accessory lobes, D. Is membranous', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) Fetal plate smaller than basal plateRef: William's obs ch-27 p.578", 'role': 'assistant'}]