according to cell theory, what do these four organisms have in common?
they are made of one or more cells.
they must undergo sexual reproduction.
they have a nucleus or control center
d)
they require carbon dioxide to produce food.

your answer is A

Explanation: they are made of one or more cells :)

The correct answer is A) They are made of one or more cells.

Explanation:

Organisms are all made of cells, which are the constitutive unit of living beings. Organisms can be made of one cell (unicellular organisms) or more than one cell (pluricellular organisms).

Option B is not correct because reproduction can be sexual and asexual.

Option C is not correct because organisms can be prokaryotic (such as bacteria) or eukaryotic (such as animal and plants).

Option D is not correct because the organisms which require carbon dioxide to produce food are plants.

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.