Organisms are classified taxonomically. One of these classifications is the kingdom. There are 5 kingdoms: animalia (animals), plantae (plants), fungi (fungi), monera (prokaryotes), and protista (other eukaryotes).
The kingdom protista specifically harbor eukaryotes that cannot be classified in the other kingdoms (plantae, animalia, fungi), some examples are algae, protozoa, or amoebae.
Because bacteria are prokaryotes (monera kingdom). The answer is C "eukaryotes".