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
A mother of 3 children had an unprotected sex last night. She didn't want to conceive that time because her last child was only 7 months old. All of the following are used for emergency contraception, EXCEPT: 
Select and explain. 
A. IUD, B. Danazol, C. Ethinyl estradiol and levonorgestrel, D. Mifepristone
B: Danazol
Answer: B: Danazol 
Explanation: Current methods of emergency contraception include combined oral contraceptives, progestin-only products, copper-containing IUDs, and mifepristone. Danazol is a 19-noestosterone derivative with progestin-like effects. Danazol acts several mechanisms to treat endometriosis. It acts at the hypothalamic level to inhibit gonadotropin release, inhibiting the midcycle surge of luteinizing hormone and follicle-stimulating hormone. Danazol also inhibits steroidogenic enzymes in the ovary that are responsible for estrogen production. Ref: Sarajari S., Muse, Jr. K.N., Fox M.D. (2013). Chapter 56. Endometriosis. In A.H. DeCherney, L. Nathan, N. Laufer, A.S. Roman (Eds), CURRENT Diagnosis & Treatment: Obstetrics & Gynecology, 11e.