How many of the following statement (s) is/are correct about pollination?

I: In Vallisneria and Zostera, the flowers emerge above the level of water and are pollinated by insects or wind.
II: In most of the water pollinated species, pollen grains are protected from wetting by a mucilaginous covering.
III: Pollination by water is quite rare in flowering plants and is limited to about 30 genera, mostly dicotyledons.