<prompt> Risk factor for bladder carcinoma isClonorcis sinensisSchistosoma hematobiumPlasmodiumNone  <response>: Answer- B. Schistosoma hematobiumCigarette smoking is the main etiological factor.Occupational exposures to chemicalsSchistosoma haemotobiumDrugs such as phenacetin chlornaphazineCyclophosphamidetherapyPelvic radiation 