A column of water within xylem vessels of tall trees does not break under its weight because of:

Transpiration pulls the water up and acts as a driving force. It involves the loss of water in the form of water vapor from the stomata of the plant. The evaporation creates a negative water vapor pressure in the surrounding cells of the leaf. Once this happens, water is pulled into the leaf from the vascular tissue, the xylem, to replace the water that has transpired from the leaf. This pulling of water, or tension, that occurs in the xylem of the leaf, will extend all the way down through the rest of the xylem column of the tree and into the xylem of the roots due to the cohesive forces holding together the water molecules along the sides of the xylem tubing. Thus, the correct answer is option C.