Answer:
A. Respiration
Explanation:
The process in which oxygen atoms are made available to the cell of animals is called cell respiration. In cell respiration the food molecules undergo process which is called food oxidization, that make it available to be absorbed by the animal cell.
<span>Eukaryotic Can't be multicellular because it's one cell, heterotrophic are organisms that feed on other organisms to get energy, and prokaryotes don't have membrane-bounded organelles</span>
The atom? gas? either one of those two would work
Simple squamous epithelium
