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': 'Which of the following statement is true about clomiphene citrate, EXCEPT: \nSelect and explain. \nA. Enclomiphene has antiestrogenic effect, B. Successful pregnancy in 15-20% of those who ovulate, C. Risk of multiple pregnancy is 6-10%, D. It can also be used for oligozoospermia', 'role': 'user'}, {'content': "Answer: B \nExplanation: Although clomiphene is effective in inducing ovulation in perhaps 75% of women, successful pregnancy ensues in only 40-50% of those who ovulate. This has been attributed to clomiphene's inhibition of estrogen action on the endometrium, resulting in an environment that is not optimal for feilization and/or implantation. Ref: Schimmer B.P., Parker K.L. (2011). Chapter 66. Contraception and Pharmacotherapy of Obstetrical and Gynecological Disorders. In L.L. Brunton, B.A. Chabner, B.C. Knollmann (Eds), Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e.", 'role': 'assistant'}]