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': 'Antihormonal substance used to induce ovulation: \nSelect and explain. \nA. Mifepristone, B. Clomiphene citrate, C. Tamoxifen, D. Raloxifen', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Extra Edge:', 'role': 'assistant'}]