Answer:
The correct answer is - cell membrane.
Explanation:
Cell membrane or plasma membrane is the outer structure that enclosed the cell-matrix and cell organelles and acts as a barrier to the substances and things to move in or out of the cell and allows only specific substances and molecules to move in and out of the cell.
If the cell membrane is not performing its function properly it might result in blocking the various nutrients and other essential molecules to move in and metabolic substances to move out of the cell.
