This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infertility, Subject name: Gynaecology & Obstetrics
[{'content': 'Drugs used for ovulation induction are: \nSelect and explain. \nA. mifeprestone, B. Clomiphene citrate, C. levonorgestrel, D. oc pills', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ovulation induction is done with clomiphene citrate with a dose of 50mg/day to maximum 250mg daily,if the ovulation is not induced by the lower dose. The actual staing day of its administaion in the follicular phase varies between day 2 and day5. Therapy is given for 5days. Mechanism of action: Clomiphene citrate is anti-estrogenic as well as weakly estrogenic. It blocks the estrogen receptors in the hypothalamus. This results in increased GnRH pulse amplitude causing increased gonadotropin secretion from the pituitary. Reference: DC Dutta's textbook of Gynaecology-7th edition-page no 199.", 'role': 'assistant'}]