Answer: Protista
Step-by-step explanation:
The kingdom Protista includes single celled eukaryotic organisms. They posses nucleus and other organelles like other eukaryotic organisms. They are simple organisms that live in water, moist or terrestrial habitats. They are either parasitic or may live in symbiotic association with other organisms. They posses cilia and flagella which facilitates their movement.
On the basis of the above description, this can be said that the observed organism will belong to kingdom Protista.