Here's why:

* Evolutionary History: Protists and animals both belong to the domain Eukarya, meaning they have cells with a nucleus and other membrane-bound organelles. Bacteria, on the other hand, belong to the domain Bacteria and are prokaryotes, lacking these internal structures.

* Common Ancestor: Protists and animals share a common ancestor that lived billions of years ago. This ancestor was likely a single-celled eukaryote. Bacteria diverged from this lineage much earlier.

* Genetic Evidence: Modern genetic analysis consistently shows that protists and animals are more closely related than protists and bacteria.

Important Note: While protists are more closely related to animals, they are a diverse group with a complex evolutionary history. Some protists are more closely related to plants or fungi than to animals.