This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ecotopic Pregnancy, Subject name: Gynaecology & Obstetrics
[{'content': 'Highest risk of ectopic pregnancy is with: \nSelect and explain. \nA. Intrauterine device, B. Surgery for previous ectopic, C. Salpingitis, D. Salpingitis isthmica nodosa', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is b. i.e. Surgery for previous ectopic(Ref: William Obs 25/e Pg 371)Surgeries for a prior tubal pregnancy for fertility restoration or for sterilization confer highest risk of Ectopic. William Obs 25/e pg 371', 'role': 'assistant'}]