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': 'Commonest presentation of bilateral ureteric stones - \nSelect and explain. \nA. CRF, B. UTI, C. Pain, D. Hematuria', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]