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': '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: Ref: Katzung 10th/891 Though surgery is the form of primary treatment in osteosarcoma but etoposide, cyclophosphamide, cisplatin and doxorubicin have been used. High dose methotrextae has been the drug of choice and is the only FDA approved agent for this condition.', 'role': 'assistant'}]