Name four types of clinically relevant protozoa.

The correct answer identifies four types of clinically relevant protozoa: amoebas, flagellates, ciliates, and sporozoans. These classifications are essential in understanding various pathogenic protozoa that can affect human and animal health.

Amoebas are characterized by their ability to move and feed using pseudopodia, with some species being known to cause diseases such as amoebic dysentery. Flagellates possess one or more whip-like flagella that aid in movement; they include notable pathogens like Giardia lamblia, which causes giardiasis. Ciliates are identified by their short hair-like structures called cilia, and while fewer are pathogenic, they are still significant in the study of protozoal infections. Sporozoans are characterized by their complex life cycles and include organisms like Plasmodium, responsible for malaria.

The other options do not accurately list types of protozoa. Some mention bacteria, fungi, and viruses, which are distinct categories of microorganisms unrelated to protozoa. Others mix categories incorrectly, combining protozoa with terms that refer to other classes of organisms, highlighting a misunderstanding of microbial classification.