The correct answer is option B, that is, it is a eukaryote that is not an animal, a plant, or a fungus.
Giardia refers to a microscopic parasite (a protist), which leads to a diarrheal disease called giardiasis. It is found in food, soil, or water, or on the surfaces, which has been contaminated with feces from infected animals or humans.
The protists are the eukaryotes, that is, their cells possess a nucleus and other membrane-bound organelles. The majority of the protists are unicellular. Other than these characteristics, the protists are considered as all the eukaryotic species, which are neither plants, animals, nor fungi.
