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: Surgery
Commonest site of intro peritoneal abscess is 
Select and explain. 
A. Lesser sac, B. Greater sac, C. Pelvis, D. None of the above
C: Pelvis
Answer: C: Pelvis 
Explanation: Pelvic abscess in the most common site of intra peritoneal abscess.