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': 'Failure rate is after tuba! sterilization with pomeroys technique \nSelect and explain. \nA. Zero, B. 0.10%, C. 0.40%, D. 1.00%', 'role': 'user'}, {'content': 'Answer: C \nExplanation: 0.40%', 'role': 'assistant'}]