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: Radiology
[{'content': 'Thickened gall bladder wall in USG seen in? \nSelect and explain. \nA. Acute cholecystitis, B. Mucosal thickening, C. Cholesterosis, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A i.e. Acute cholecystitis; B i.e. Mucosal thickening; C i.e. Cholesterosis', 'role': 'assistant'}]