Entamoeba histolytica is a protozoan parasite that causes amoebiasis, a disease of the large intestine. It is the only protozoan that can cause invasive disease in humans. The parasite is found in tropical and subtropical regions of the world, and is spread through contaminated food and water.
A virus is a small infectious agent that replicates only inside the living cells of other organisms. Viruses are not considered to be living things because they do not have the ability to reproduce on their own.
A bacterium is a single-celled organism that is a prokaryote, meaning that it does not have a nucleus or other membrane-bound organelles. Bacteria are found in all environments, and some are beneficial to humans, while others can cause disease.
A fungus is a eukaryotic organism that is not a plant or animal. Fungi are found in all environments, and some are beneficial to humans, while others can cause disease.
The correct answer is: B. Protozoan