This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urinary Bladder, Subject name: Pathology
Transitional cell carcinoma bladder caused by- 
Select and explain. 
A. Schistosomiasis, B. Ascariasis, C. Malaria, D. None
A: Schistosomiasis
Answer: A: Schistosomiasis 
Explanation: Ans. is 'a' i.e., Schistosomiasis Risk factors for transitional ceil carcinoma (TCC) of bladder -Smoking - Major etiological factor.Occupational exposure to chemicals - Nephthylamine benzidine, aniline dyes, acrolein.Schistosoma haematobium (Bilharziasis) - It is a risk factor for both TCC & SCC.Drugs - PhenacetinCyclophosphamide therapyPelvic irradiations