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': 'Decidualization of endometrium is due to \nSelect and explain. \nA. Estrogen, B. Progesterone, C. Inhibin, D. FSH', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Progesterone is responsible for decidualization of endometrium.', 'role': 'assistant'}]