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
Which of the following is not an indication for cholecystectomy: 
Select and explain. 
A. 70 year old male with symptomatic gall stone, B. 20 years old male with sickle cell anemia and symptomatic gallstones, C. 65 year old female with a large gallbladder polyp, D. 55 year old with an asymptomatic gallstone
D: 55 year old with an asymptomatic gallstone
Answer: D: 55 year old with an asymptomatic gallstone 
Explanation: Answer is D (55 year old with an asymptomatic gallstone): Prophylactic cholecystectomy is not warranted in an asymptomatic patient.