This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sterilisation surgeries, Subject name: Gynaecology & Obstetrics
Which of the following is the most common site of tubal ligation: 
Select and explain. 
A. Ampulla, B. Isthmus, C. Interstitial, D. Fimbria
B: Isthmus
Answer: B: Isthmus 
Explanation: In India tubal ligation is still done by the Pomeroy operation and entry is mostly by Minilap, though Laparoscopic procedures have increased substantially. A loop is made by holding the tube by an allis forceps in such a way that the major pa of the loop consists of isthmus i.e. at the junction of proximal and middle third. Isthemic sterilization is best since , if required, a re anastomosis at the isthmo isthmic site has the best chance of success