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': 'In treatment of osteosarcoma, all of the following are used EXCEPT : \nSelect and explain. \nA. High dose methotrexate, B. Cyclophosphamide, C. Vincristine, D. Doxorubicin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]