The correct answer is option 2 - Mitochondria. Mitochondria are organelles that are only found in eukaryotic cells and are responsible for energy production through aerobic respiration. Prokaryotic cells, on the other hand, do not contain mitochondria.

Let`s look at the other options to understand why they are not the correct answer:

1) Option 1 - Cell wall: The cell wall is a structure found in both prokaryotic and eukaryotic cells. However, the composition of the cell wall can differ between the two types of cells. Prokaryotic cells have a cell wall made of peptidoglycan, while eukaryotic cells may have a cell wall made of cellulose, chitin, or other substances.

3) Option 3 - Plasma membrane: The plasma membrane, also called the cell membrane, is present in both prokaryotic and eukaryotic cells. It forms a boundary around the cell and regulates the movement of substances in and out of the cell.

4) Option 4 - Ribosome: Ribosomes are found in both prokaryotic and eukaryotic cells. They are responsible for protein synthesis. However, there may be some differences in