The correct answer is A. Xylem.
Xylem is a vascular tissue in plants that transports water and minerals from the roots to the leaves. It is made up of dead cells that have been thickened and lignified, which makes them strong and rigid. Xylem cells are arranged in tubes, which allows water to flow up the plant from the roots to the leaves.
Phloem is another vascular tissue in plants that transports food from the leaves to the rest of the plant. It is made up of living cells that are connected by sieve tubes. Phloem cells are arranged in bundles, which allows food to flow through the plant.
The cortex is the layer of cells that lies between the epidermis and the stele of a plant. It is made up of living cells that are involved in storage, photosynthesis, and transport.
Therefore, the correct answer is A. Xylem.