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
[{'content': 'Commonest site for ischemic colitis is - \nSelect and explain. \nA. Hepatic flexure, B. Splenic flexure, C. Descending colon, D. Ascending colon', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans is \'b\' ie. Splenic flexure "Although splenic flexure is the most common site of ischemic colitis, any segment of colon may be affected. The rectum is relatively spared because of its rich collateral circulation."', 'role': 'assistant'}]