when oxygen availability drops certain cells in the kidney respond by producing a hormone called which in turn stimuate

Ithink option a is correct because you cannot donate a different blood group than yours because it won't match.option a says betsy can donate to mark. they have the same blood group so donation can happen.

D.) domain, kingdom, phylum, class, order, family, genus then species

Molecules called lipids have long hydrocarbon chains that determine the way they act. they can be fats, oils, or hormones, and even exist in our cell membranes