15. All the following involves osmosis except

(a)  Water from soil entering a root hair

(b)  Water passing from root hair to adjacent cells

(c)   Water passing up a xylem vessel element to xylem vessel element above it

(d)          Water entering a mesophyll cell from xylem vessel element

Ans. (c)      In xylem vessels water rises due to the transpiration pull and the cohesive power of water molecules.