Which is the best characteristic that distinguishes the kingdom archaebacteria from the kingdom eubacteria?
o
cell wall structure
body type
nutrition source
presence of a nucleus

Cell wall structure

it's anything that aren't producers and consumers.

explanation:

you've got to be clear on what "this" is

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.