The correct answer is option 2: Cell wall.

Mitochondria, which are responsible for producing energy in cells, are present in both plant and animal cells. Therefore, option 1 is incorrect.

Cell membrane, also known as the plasma membrane, is the outer protective covering of all cells. It is found in both plant and animal cells. Thus, option 3 is incorrect.

Vacuoles, which are responsible for storing water, nutrients, and waste products, are present in both plant and animal cells. However, plant cells typically contain a large central vacuole, while animal cells have smaller vacuoles. Nevertheless, vacuoles are not exclusive to plant cells. Thus, option 4 is incorrect.

The cell wall is a rigid outer layer made of cellulose that provides structure, support, and protection to plant cells. It is absent in animal cells. This makes option 2 the correct answer.

Overall, only the plant cell contains the organelle mentioned in option 2 - the cell wall.