Which of the following classes of protozoa is totally parasitic?
A. Ciliata
B. Sporozoa
C. Sarcodina
D. Mastigophora

Hint: The Apicomplexa are a broad phylum of parasitic alveolates. Most of them have an uncommon outline of organelle that comprises a sort of plastid called an apicoplast, and an apical complex structure.

Complete answer:
The ciliates are a bunch of protozoans characterized by the closeness of hair-like organelles called cilia, which are vague in structure to eukaryotic flagella, but are in common shorter and appear in much greater numbers, with a different undulating plan than flagella. The Sporozoa is the fifth phylum of kingdom protista which are parasitic. These protozoans do not have locomotory organs. They do not have cilia, flagella or pseudopods for movement. They are more regularly than not passed from one ought to another have encased inside a cautious capsule, which are called 'spores'. These spores additionally encase juvenile states or zygotes. Sarcodina, the greatest phylum (11,500 living species and 33,000 fossil species) of protozoans). It comprises the amebas and related living creatures; all single cells that move and capture food by suggests of pseudopods, gushing passing developments of the cell. Most sarcodines are free living; others are parasitic. Notwithstanding, people of the accumulate are characterized by the closeness of one of a couple of flagella utilized for improvement and are in this way as well insinuated to as flagellates. They can be found in terrestrial and maritime circumstances where they may exist as free-living life shapes or as parasites.

Hence, the correct answer is option (B).

Note: Sporozoans are life shapes that are characterized by being one-celled, non-motile, parasitic, and spore-forming. Most of them have a variety of sexual and abiogenesis stages in their life cycle.