This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
[{'content': 'Hemorrhagic cystitis is caused by \nSelect and explain. \nA. Cyclophosphamide, B. 6 mercaptounrine, C. 5 flurouracil, D. Busulfan', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Refer Katzung 11/e p500 It is a prodrug and is activated BBy hepatic biotransformation to aldophosphamade. One of the degradation products is acrolein that is responsible for hemorrhagic cystitis', 'role': 'assistant'}]