This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy: General Principles, Subject name: Pharmacology
[{'content': 'Sodium 2-mercapto ethane sulfonate is used as a protective agent in: \nSelect and explain. \nA. Radiotherapy, B. Cancer chemotherapy, C. Lithotripsy, D. Hepatic encephalopathy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (B) Cancer chemotherapy(Ref: KDT 8th/e p919)Sodium-2-mercapto ethane sulfonic acid (mesna) is used to ameliorate the hemorrhagic cystitis caused by cyclophosphamide and ifosfamide.', 'role': 'assistant'}]