The Xylem in plants is responsible for transporting -

In vascular plants, xylem is the specialized tissue responsible for the conduction of water and dissolved minerals from the roots to the stems and leaves. It also provides structural support to the plant. The transport in xylem is typically unidirectional (upwards).

• Phloem is responsible for transporting organic nutrients, such as food (sucrose) and amino acids, from the leaves to other parts of the plant (translocation).
• Oxygen and carbon dioxide are primarily exchanged through stomata in leaves and lenticels in stems via the process of diffusion.

Therefore, the primary function of xylem is the transport of water.