Water is said to travel from the roots of a tree to the uppermost branches via capillary action. assuming that the smallest capillaries observed in plant material have diameters of 20 µm and that the surface tension of water is 0.065 n/m, how high can water rise in such a capillary? what does your answer say about the mechanism in question?

Water  molecules stay close to each other through cohesion, the collective action of hydrogen bonds between water molecules. Cohesion helps plants draw water upwards from the root through the stem's transport tubes (xylem) to the leaf. This transport occurs even in large trees and against gravity. Transpiration, evaporation of water from plant leaves, creates a tension on water molecules being pulled up from the stem and roots.

The answer should be a.