The correct option is A The flowers are brightly coloured and produce nectar.
Insect pollinated flowers usually are brightly coloured and produce nectar. The water pollinated flowers are usually dull and do not produce nectar.
Vallisneria and Hydrilla are water pollinated plants.
In most of the water pollinated species, pollen grains are protected from wetting by a mucilaginous covering.
In seagrasses, the pollen grains are usually long, ribbon-like and are carried passively inside the water.