Amoeba is a single-celled organism that belongs to the group of protists. Protists are eukaryotic organisms, which means that their cells have a nucleus and other organelles. They are not plants, animals, or fungi. There are many different types of protists, and they can live in a variety of habitats, including water, soil, and even on other organisms.
Bacteria are also single-celled organisms, but they are prokaryotic, which means that their cells do not have a nucleus or other organelles. Bacteria are found in almost every environment on Earth, and they play an important role in the cycling of nutrients.
Fungi are multicellular organisms that are eukaryotic. They are found in a variety of habitats, including soil, water, and on other organisms. Fungi play an important role in the decomposition of organic matter.
The correct answer is A. Protozoa.