A physician orders GARAMYCIN 4 mg/kg/day divided into three 50 mL piggybacks to be administered q8h to a 144-pound adult. The stock strength available is GENTAMICIN 40 mg/mL in 20-mL multi-dose vials. How many mL should be added to each piggyback? O 2.2 mL O 2.9 mL O 6.6 mL 0 9.2 mL