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 factor for Squamous cell tumor of urinary bladder 
Select and explain. 
A. Schistosomiasis, B. Bladder diverticulum, C. Chronic cystitis, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Schistosomiasis and chronic cystitis are risk factors for SCC Bladder.