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': 'In a case of dysfunctional uterine bleeding thehormone which is usually deficient is : \nSelect and explain. \nA. Oestrogen, B. Progesterone, C. Thyroxin, D. A.C.T.H.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Progesterone', 'role': 'assistant'}]