The correct option is B Epihydrophily
Pollination
in Vallisneria is epihydriphilous. It is a type of hydrophily which occurs on
the surface of water. The female flower have a very long pedicel, therefore it
reaches the surface of water. Male flowers after breakage floats on the surface
of water. Pollen grains are released on to the surface of water. They are
carried passively by water currents, some of them eventually reach the female
flowers and the stigma.