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': 'Normal capacity of the renal pelvis is - \nSelect and explain. \nA. 7 ml., B. 10 ml, C. 15 ml, D. 20 ml', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., 7 ml", 'role': 'assistant'}]