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': 'Drug useful in breast cancer is \nSelect and explain. \nA. Tamoxifen, B. Cyprotenene, C. Testosterone, D. Chlorambucil', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Medications Estrogen modulator, Chemotherapy, Hormone based chemotherapy, and Bone health', 'role': 'assistant'}]