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': 'Fecundability is \nSelect and explain. \nA. Probability to achieve a live birth within one menstrual cycle, B. Probability to achive pregnancy within one menstrual cycle, C. Probability to achive a twin pregnancy within one menstrual cycle, D. Probability to achive a live birth within one year of treatment for infertility', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Fecundability is probability to achive pregnancy within one menstrual cycle.', 'role': 'assistant'}]