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: Physiology
In the formula for urea clearance, C = U x V/P, U denotes: 
Select and explain. 
A. Urinary concentration in gm/24 hours, B. Urine osmolarity, C. Urinary concentration in mg/ml, D. Urine volume per minute
C: Urinary concentration in mg/ml
Answer: C: Urinary concentration in mg/ml 
Explanation: Ans: C. Urinary concentration in mg/ml In the Given Formula:C = Clearance of the substanceU = Urinary concentration of the substance in mg/mlP = Plasma concentration of the substance in mg/mlV = Volume of urine