This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infeility (Eggs'plantation!), Subject name: Gynaecology & Obstetrics
[{'content': 'In the perspective of the busy life schedule in the modern society, the accepted minimum period of sexual cohabitation resulting in no offspring for a couple to be declared infeile is: \nSelect and explain. \nA. One year, B. One and a half-year, C. Two years, D. Three year', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 90% of couple who are cohabiting for at least one year with out contraception will have a conception. This is on monthly conception rates of 20 - 25 % in normal young couples attempting pregnancy.', 'role': 'assistant'}]