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': 'All are alkylating agents, except \nSelect and explain. \nA. 5-Fluorouracil, B. Melphalan, C. Cyclophosphamide, D. Chlorambucil', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (A) 5-Fluorouracil(Ref: Katzung 11th/e p945, KDT 8th/e p918-919)5-Fluorouracil is an antimetabolite whereas melphalan, cyclophosphamide and chlorambucil are alkylating agents.', 'role': 'assistant'}]