This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Non communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'Lowest expulsion rate of IUD - \nSelect and explain. \nA. Lippers loop, B. LNG, C. Progestase, D. CuT-220', 'role': 'user'}, {'content': "Answer: C \nExplanation: Park's textbook of preventive and social medicine 23rd edition. *expulsion rate of lippes loop-12 to 20% *progestase-2.7%. *LNG- 6%.", 'role': 'assistant'}]