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': "Chemotherapy is not useful in : \nSelect and explain. \nA. Chondrosarcoma, B. Wilm's tumor, C. Choriocarcinoma, D. All", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]