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': 'Levonorgestrel IUS used in treatment of AUB, has all benefits except \nSelect and explain. \nA. Provides contraceptive cover, B. Effective for associated dysmenorrhea, C. No break-through bleeding, D. Women become amenorrheic within one year after insertion', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Irregular menses and break through bleeding occurs for first 3\xa0→ 9 months after insertion.', 'role': 'assistant'}]