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': 'A couple is advised to use barrier methods after vasectomy till : \nSelect and explain. \nA. 3 months, B. No sperms in ejaculate, C. Next 15 ejaculations, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: It is imperative that some other contraception should be used for the next three months or 15 ejaculation. At the end of the period semen analysis should be done to confirm the absence of sperm in the ejaculate. TEXTBOOK OF GYNECOLOGY SHEILA BALAKRISHNAN SECOND EDITION PAGE NO 396', 'role': 'assistant'}]