Consider a drug which is exogenous to the body. The drug is filtered, but not secreted, reabsorbed, or metabolised by the kidneys.

Consider a drug which is exogenous to the body. The drug is filtered, but not secreted, reabsorbed, or metabolised by the kidneys. The drug is constantly infused in a patient to maintain a plasma concentration of 2mg/L. 24 hour urine collection shows the drug being excreted at a rate of 400μg/min. What is this patient's GFR?

A. 50ml/min

B. 100ml/min

C. 150ml/min

D. 200ml/min

E. 400ml/min