This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contraception, Subject name: Gynaecology & Obstetrics
[{'content': 'Which is not an emergency contraceptive : \nSelect and explain. \nA. Combined oral pills, B. Estrogen, C. Desogestrel, D. Levonorgestrel', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Emergency contraception: The preparations available include Two tablets of relatively high doses of combined pill containing 100mcg of EE2 and 1 mg norethisterone or 500 mcg LNG taken within 72 hrs of intercourse Others include LNG tablets Mifepristone Ulipristal Centchroman Prostaglandins Copper T IUCD Ref: Shaw Gynecology 17 e pg 270.', 'role': 'assistant'}]