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': 'Least failure in sterilization occurs with: \nSelect and explain. \nA. Falope ring, B. Bipolar cautery, C. Unipolar cauterisation, D. Hulka clip', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Female tubal sterilization methods-10 year cumulative failure rates:\nUnipolar cauterisation – 0.75%\nPostpartum tubal excision – 0.75%\nSilastic ring/fallope ring – 1.77\nInterval tubal exclusion – 2.01\nBipolar coagulation – 2.48\nHulka - clemens clips – 3.65\nNote: Although unipolar cauterization has least failure rates, but is not preferred method for female steriliization as it leads to serious gastrointestinal burns.', 'role': 'assistant'}]