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': 'Which of the following drugs is Topoisomerase 1 inhibits \nSelect and explain. \nA. Doxorubicin, B. Irinotecan, C. Etopside, D. Vincristine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Refer KDT 6/e p 825, Camptothecin derivatives like topotecan and irinotecan act by inhibiting Topoisomerase -1whereras epipodophylotoxins and anthracycline act by inhibiting Topoisomerase -2', 'role': 'assistant'}]