Modern cetaceans, the taxonomic group that includes whales, dolphins, and porpoises, evolved from land mammals. however, it has only been within the past few decades that transitional fossils have been found that have shed light on cetacean hindlimb reduction. dna data suggest that cetaceans are most closely related to hippos, which are even-toed ungulates. other even-toed ungulates include deer, pigs, camels, and cows. which statement describes most accurately how the early cetacean, pakicetus, fossil ankle bones shown in the figure supports the hypothesis that cetaceans are closely related to even-toed ungulates?

Taxonomy may be defined as the branch of biology that mainly deals with the classification, arrangement and nomenclature of the organism. Organism are classified into the different taxa depending on their similarities and differences.

The shared characters may be defined as the characters that are share among the two lineages. As given in the question, the two humps that are present on the bottom end of  Pakicetus ankle bone is the shared distinguish character with the other ungulates that are even toed.

what school and grade?

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem