This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Anatomy
A most common tumour of urinary bladder is 
Select and explain. 
A. Squamous cell carcinoma, B. Adenocarcinoma, C. Stratified squamous carcinoma, D. Transitional carcinoma
D: Transitional carcinoma
Answer: D: Transitional carcinoma 
Explanation: 3 histological types of Bladder cancer are seen transitional cell ca -90% squamous cell ca -5~10% adenocarcinoma - 2%