Final answer:
The domain that encompasses all eukaryotic kingdoms is Eukarya, which includes organisms with nuclei in their cells and is distinct from the prokaryotic domains Archaea and Bacteria.
Step-by-step explanation:
The domain that contains all eukaryotic kingdoms is Eukarya. The domain Eukarya is characterized by organisms that have cells with nuclei, which includes the kingdoms of plants, animals, fungi, and several kingdoms of protists.
Contrastingly, the Archaea and Bacteria domains consist of prokaryotic organisms that do not have a cell nucleus. The Archaea are known for inhabiting extreme environments, whereas the Bacteria can be found in a variety of environments.
The inclusion of the domain level above the kingdom in the taxonomic system reflects the major differences in the genetic and biochemical composition of the three groups, leading to a more accurate representation of life's diversity as understood through modern science.