The Centers for Disease Control and Prevention (CDC) recommends that public health actions be initiated when the level of lead in a child’s blood is 5 micrograms per deciliter (µg/dL) or more. What is this in ppm? ( 1 dL = 0.1 dm^3)

a) 5 ppm
b) 0.5 ppm
c) 50 ppm
d) 0.05 ppm