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': 'Risk factors for malignant change in an asymptomatic patient with a gall bladder polyp on ultrasound include all of the following, Except: \nSelect and explain. \nA. Age > 60 years, B. Rapid increase in size of polyp, C. Size of polyp > 5 mm, D. Associated Gall stones', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]