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': 'Which one of the following intrauterine contraceptive devices has the lowest pregnancy rate \nSelect and explain. \nA. Lippes loop, B. Cu - 7, C. Cu T - 200, D. Levonorgestrel IUD', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Levonorgestrel IUD', 'role': 'assistant'}]