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
Normal capacity of the renal pelvis is 
Select and explain. 
A. 7 ml, B. 10 ml, C. 15 ml, D. 20 ml
A: 7 ml
Answer: A: 7 ml 
Explanation: • The average capacity of the renal pelvis is 4–8 ml.