The correct answer is Protista.
Protists refer to the eukaryotic species, which cannot be categorized as animal, plant, or fungus. They are in majority unicellular, however, some of them are like algae, and are multicellular.
The protists can be heterotrophic that is, in order to obtain the energy they require to live by consuming other species. They can also be autotrophic, that is, they can obtain their energy from the surrounding by the process of photosynthesis.
These species are found mainly in water, though some of them are also found in moist soil. They can be found almost any place in the world, where there is water.