Capillary action is due to the

Capillary action is the phenomenon by which a liquid rises or falls in a narrow tube or small space due to the combined effects of surface tension, cohesion, and adhesion.

Surface tension is the property of a liquid that causes its surface to behave like a stretched elastic membrane. It acts to minimize the surface area of the liquid and plays a crucial role in capillary movement.

Cohesion refers to the intermolecular attraction between molecules of the same liquid. It tends to pull the liquid molecules together and resists deformation of the surface.

Adhesion refers to the attractive forces between the liquid molecules and the molecules of the solid surface (such as the walls of the capillary tube). When adhesion is stronger than cohesion, the liquid rises in the tube (as in water). When cohesion is stronger than adhesion, the liquid level falls (as in mercury).

Thus, capillary action results from the combined effect of all three — surface tension, cohesive forces, and adhesive forces.

Therefore, the correct answer is Option D: All of the above.