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': 'Hydatidiform mole is principally a disease of- \nSelect and explain. \nA. Amnion, B. Chorion, C. Uterus, D. Decidua', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Hydatidiform or vesicular mole is an abnormal pregnancy characterized by hydropic degeneration and avascularity of the chorionic villi and trophoblastic proliferation.The resultant conceptus appears as grape like cystic vesicles called moles (refer pgno:169 sheila textbook of obstetrics 2 nd edition)', 'role': 'assistant'}]