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': 'Which of the following is radiolucent stone \nSelect and explain. \nA. Calcium oxalate, B. Struvite, C. Cystine, D. Uric acid stones', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Uric acid stones are radiolucent. These are seen in during increased uric acid production such as tumor lysis\nsyndrome.', 'role': 'assistant'}]