Water has surface tension because ...

molecules at the surface make more hydrogen bonds.
there is positive pressure inside the water mass.
hydrogen bonds between surface water molecules resist being stretched.
water tends to evaporate from the surface.
cohesion forces are weaker at the surface.

1 answer

Water has surface tension primarily because hydrogen bonds between surface water molecules resist being stretched. At the surface, water molecules are subjected to different forces than those in the bulk of the liquid. While molecules in the interior are surrounded by other water molecules and experience balanced attractive forces in all directions, surface molecules experience a net inward force due to the absence of water molecules above them. This results in a strong cohesive force among the surface molecules, contributing to the phenomenon of surface tension.

So the best answer is: hydrogen bonds between surface water molecules resist being stretched.