Answer:
A) cell wall
Step-by-step explanation:
The cell wall does not help differentiate prokaryotic cells from eukaryotic cells, since both have the cell wall (formed by polysaccharides and amino acids).
The other structures help identify the eukaryotic cell due to the fact that only this type of cell has them, while prokaryotic cells lack organelles such as mitochondria and the golgi complex.
In addition, prokaryotes do not have membrane-bound nuclei, and due to their less complex structure, their genetic material is dispersed in the cytoplasm.