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: Pharmacology
[{'content': 'Clomiphene is - \nSelect and explain. \nA. Antiprogestin, B. Antiestrogen, C. Antiandrogen, D. Antidiabetecs', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Antiestrogen o It acts as a pure estrogen antagonist in all human tissues.", 'role': 'assistant'}]