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: Social & Preventive Medicine
[{'content': 'Highest pregnancy rate is associated with \nSelect and explain. \nA. Lippies loop IUD, B. Copper T IUD, C. Progestatsert IUD, D. LNG - IUD', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]