For which one of the following is capillarity not the only reason?

1. The question asks for which phenomenon capillarity is not the *only* reason. 2. Capillarity (or capillary action) is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. It arises due to intermolecular forces between the liquid and the surrounding solid surfaces (adhesion) and within the liquid itself (cohesion). 3. Blotting of ink: Ink is drawn into the pores of blotting paper primarily due to capillary action. 4. Rising of underground water: Water rises in soil pores due to capillary action, although factors like water table pressure are also involved. 5. Spread of water drop on a cotton cloth: Water spreads through the fine fibers of cotton cloth mainly due to capillary action. 6. Rising of water from the roots of a plant to its foliage: This process, called ascent of sap, involves multiple factors. While capillarity in the narrow xylem vessels plays a role, the primary drivers are transpiration pull (cohesion-tension theory) and root pressure. Therefore, capillarity is not the sole reason.