Answer:
Phylum
Step-by-step explanation:
In the biological classification system, categories are used to group organisms according to their similarities. The basic category is species, which is defined as similar beings who are able to reproduce naturally and generate fertile descendants.
Animals of the same species are grouped into another category, the genus. All who belong to the same genre are grouped into families, which are grouped into orders, which in turn come together in classes, assembled in phyla, and finally we have the kingdoms. Kingdoms are therefore the last category in the hierarchy and subdivided into the most basic category. So we have:
Kingdom ⇒ Phylum ⇒ Class ⇒ Order ⇒ Family ⇒ Gender ⇒ Species
From this we can conclude that the level of organization in the classification system that is directly above the level of "class" is the "phylum".