Cell wall is present only in plants, it is not found in all organisms. Compared to the cell
membrane, a cell wall is thick and has a rigid structure. You can see it in a
light microscope, because it is visible. It serves as the protective cover that
surrounds the plasma membrane in a plant cell. Cell membrane is composed of
lipids. Cell walls can be made up of cellulose or peptidoglycan or chitin. The
answer is D.
