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
Which is a normal finding in cystometry 
Select and explain. 
A. Absence of systolic detrussor contraction, B. Residual volume of 75 ml, C. Leakage on coughing, D. First sensation of urination at 300 ml
A: Absence of systolic detrussor contraction
Answer: A: Absence of systolic detrussor contraction 
Explanation: None