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
A Most common tumor of the urinary bladder is - 
Select and explain. 
A. Sq. cell carcinoma, B. Adeno carcinoma, C. Transitional carcinoma, D. Str. squamous carcinoma
C: Transitional carcinoma
Answer: C: Transitional carcinoma 
Explanation: There are 3 common histological types of bladder cancer 

Transitional (urothelial) cell ca - ~90%
Squamous cell ca - ~5-10%
Adenocarcinoma - ~2%