Biology homework help. Now consider a drug which is being constantly infused into a patient to establish a plasma concentration of 2mg/L. GFR in this patient is 150ml/min. The substance appears in the urine at a rate of 200?g/min. The substance is being filtered, and is not metabolised. What do we know about the handling of this substance in the nephron? Select 2 answers.1. The substance must be reabsorbed.2. The substance must not be reabsorbed.3. We can’t know from these data if the substance is being reabsorbed.4. The substance must be secreted.