This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
The completeness of a 24-hour urine collection is best assessed by the simultaneous measurement of urinary 
Select and explain. 
A. Volume, B. Urea, C. Creatinine, D. pH
C: Creatinine
Answer: C: Creatinine 
Explanation: Creatinine a nitrogenous compound formed as the end product of creatine metabolism. It is formed in the muscle in relatively small amounts, passes into the blood and is excreted in the urine. A laboratory test for the creatinine level in the blood may be used as a measurement of kidney function.Ref: Ganong&;s review of medical physiology; 24th edition; page no; 684