The correct choice is (b) 1-20 years
The best I can explain: Calculation of creatinine clearance involves the determination of serum creatinine levels. Creatinine production varies with age, height and gender. The given formulae is used to measure the creatinine level in children 1-20 years of age. Clcr is creatinine clearance in ml/min, Scr is serum creatinine in mg%, H is height in cms, W is weight in kg.