Speed up chemical reactions (Catalysts)
First of all, the cohesive and adhesive properties of the water molecules fascilitate this. Water molecules stick together and with the walls of the vessels, creating a column of water which doesn t break easily. Moreover the xylem vessels of the tree are very narrow increasing the pressure. Finally, transpiration is taking place as water from the leaves evaporate, thus a continuous osmotic gradient is being created, causing water to be drawn up the tree
x or y because both can cause it
Addition, you added an extra T between the first A and C