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: Surgery
[{'content': 'Stone which is resistant to lithiotripsy \nSelect and explain. \nA. Calcium oxalate, B. Triple phosphate stone, C. Cystine stone, D. Uric acid stone', 'role': 'user'}, {'content': 'Answer: C \nExplanation: lithiotripsy\xa0 is a medical procedure involving the physical destruction of hardened masses like kidney stones.', 'role': 'assistant'}]