A nurse is preparing to administer tobramycin 2.5 mg/kg IM to a preschooler who weighs 20 kg. Available is tobramycin injection 40 mg/mL. How many mL should the nurse administer per dose?

a) 0.5 mL
b) 1.0 mL
c) 1.5 mL
d) 2.0 mL