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
Risk factors for malignant change in an asymptomatic patient with a gall bladder polyp on ultrasound include all of the following, Except: 
Select and explain. 
A. Age > 60 years, B. Rapid increase in size of polyp, C. Size of polyp > 5 mm, D. Associated Gall stones
C: Size of polyp > 5 mm
Answer: C: Size of polyp > 5 mm 
Explanation: None