Causes diffusion of new water molecules out of the xylem and into the leaf.

1.transpiration
2.pollination
3.photosynthesis
4.none of the above

1. Transpiration

Explanation:

Transpiration is a physiological process by which plants lose water in the form of vapours through the aerial parts of a plant. Transpiration may be stomatal, cuticular or lenticular. But most of the transpiration is carried out through stomata. It is a wasteful process but it is necessary for the plants as it promotes water absorption and gives a cooling effect to the plants.  

None of the above :]