This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Female Sterilization, Subject name: Gynaecology & Obstetrics
The most common site of ligation in female sterilisation is: 
Select and explain. 
A. Isthmus, B. Ampullary, C. Cornual, D. Fimbrial
A: Isthmus
Answer: A: Isthmus 
Explanation: Ans. is 'a' i.e. Isthmus Ligation and Tubectomy in the process of tubal sterilization is most commonly preferred in the proximal isthumic portion of the fallopian tube.