Which statement accurately defines protozoa within the Protista kingdom?

Protozoa are accurately defined as unicellular eukaryotic organisms within the Protista kingdom. This classification is based on their cellular structure, which features a complex organization including a defined nucleus and organelles, distinguishing them from prokaryotic organisms that lack such structures. Protozoa are diverse and can be found in various environments, often exhibiting behaviors associated with animal-like functions, such as movement and predation. This unicellularity is a key characteristic, as all protozoa are single-celled, unlike multicellular eukaryotes, which comprise organisms such as plants and animals. Thus, the identification of protozoa as unicellular eukaryotes is fundamental to understanding their biology and ecological roles.