<prompt> Sodium 2-mercapto ethane sulfonate is used as a protective agent in:RadiotherapyCancer chemotherapyLithotripsyHepatic encephalopathy  <response>: Ans. B Cancer chemotherapyRef: KDT 8the p919Sodium-2-mercapto ethane sulfonic acid mesna is used to ameliorate the hemorrhagic cystitis caused by cyclophosphamide and ifosfamide. 