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': 'Expulsion rate following intrauterine device inseion is: \nSelect and explain. \nA. 1%, B. 5%, C. 20%, D. 30%', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Expulsion rates vary between 12 to 20%. Expulsion rates depend on clinical skill, timing of inseion and age and parity of the user. Ref: Park, 22nd edition pg: 459', 'role': 'assistant'}]