This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contraceptives, Subject name: Gynaecology & Obstetrics
[{'content': 'Contraceptive LNG-IUD (levonorgesterol intra-uterine device) has the cumulative pregnancy rate at 5 yrs of: \nSelect and explain. \nA. 0.5, B. 1, C. 1.5, D. 2', 'role': 'user'}, {'content': 'Answer: A \nExplanation: This is the closest choice in reference to the claimed rate by the manufacturer after phase three trials where the five-year cumulative pregnancy rate is 0.7 percent.LNG-IUD releases approximately 20 mcg levonorgestrel per day initially then 10 mcg /day. LNG does not increase the risk of PID. Lesser ectopic pregnancy as compared with copper devices.', 'role': 'assistant'}]