The correct options are
A water lily
B lotus
Seed dispersal by water takes place in aquatic plants. Aquatic plants are the plants that live in water. Water lilly is an aquatic plant.
Plants that live on land are called terrestial plants.
Generally, for terrestial plants, mode of seed dispersal is other than water, like wind, explosion or gravity.
For example, in dandelion plants, seed is dispersed by wind. However, plants like coconut can spread the seeds by water.
Seed dispersal in cucumber occurs by explosion.