Hint: Epihydrophily is a type of pollination in Vallisneria. Pollination is the act of transfer of the pollen grains from the male anther of a flower to the female stigma of the plant. The ultimate aim of every living organism, including plants, is to produce offspring for the further generation.
One of the ways that plants can give birth to offspring is by making seeds. Seeds are the genetic information needed to produce a new plant. Flowers are the tools that plants use to give birth to their seeds. Seeds can only be given when pollen moves between flowers of the same species. It is a type of hydrophilicity that occurs on the surface of the water.
Additional information: The female flower has a very long pedicel, so it reaches the surface of the water. The male flowers after the broken float on the surface of the water. They are passively carried by streams of water, some of them eventually reaching the female flowers and stigma. In the water these pollen grains are released. The pollen grains are long, threadlike, and carried with the water and go to the stigma and reach the pollination.
So, the correct answer is Water.
Note: Pollination in Vallisneria is done with water. The female flowers of Vallisneria are submerged in water. They reach the water surface by the long stalk when they reach maturity. At this time, the male flowers are released to the surface of the water. With the help of water, the pollens come into contact with the female flowers and pollination takes place, in the case of the water lily, the female flowers are submerged in the water