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: Medicine
Which of the following has the worst prognosis 
Select and explain. 
A. Cholecystectomy, B. Splencetomy, C. Nephrectomy, D. Appendicetomy
B: Splencetomy
Answer: B: Splencetomy 
Explanation: None