This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': "Melphalan is used in - \nSelect and explain. \nA. Multiple myeloma, B. Wilm's tumour, C. Neuroblastoma, D. Retinoblastoma", 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Multiple myeloma o Melphalan is an anticancer (alkylating) agent which is most effective in multiple myeloma.", 'role': 'assistant'}]