This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
[{'content': 'Features suggestive of Acute cholecystitis on CT abdomen are all Except \nSelect and explain. \nA. Pericholecystic fluid, B. Presence of gallstones, C. Contratcted gall bladder, D. Air in the gallbladder wall', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Diagnostic criteria for acute cholecystitis on CT includemajor criteriagallstonesthickened gallbladder wallpericholecystic fluid collectionssubserosal oedemaminor criteriagallbladder distentionsludgeContraction of the gallbladder is sen in cholelithiasis, not acute cholecystitis.', 'role': 'assistant'}]