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 65 year old male smoker presents with gross total painless hematuria. The most likely diagnosis is ? 
Select and explain. 
A. Carcinoma of urinary blader, B. Benign prostatic hyperplasia, C. Carcinoma prostate, D. Cystolithiasis
A: Carcinoma of urinary blader
Answer: A: Carcinoma of urinary blader 
Explanation: Ans. is 'a' i.e., Carcinoma of urinary bladder "Painless haematuria is by far the most common symptom and should be regarded as indicative of bladder carcinoma unless proven otherwise." Bailey Cigarette smoking is the main etiological factor for bladder cancer.