Biology · Kingdom Protista

The correct answer is 'Sporozoa' because this class includes protozoans that are exclusively parasitic. They do not possess locomotor organelles such as cilia, flagella, or pseudopods, and they reproduce through spore formation. 'Protozoa' is a general term, not a class, and includes various non-parasitic organisms. 'Plasmodium' is a genus within the Protozoa, not a class, and while all its species are parasitic, it does not encompass the entire class level of classification. 'Ciata' is not a recognized term in protozoan taxonomy.

This option is incorrect because 'Protozoa' is a broad category encompassing various single-celled eukaryotic organisms. While some protozoans are parasitic, many are not, making this option too general to be correct.

This option is incorrect because 'Plasmodium' refers to a specific genus within the protozoan classification. Although all Plasmodium species are parasitic, the question asks for a class, not a genus.

This option is incorrect as 'Ciata' appears to be a typographical error or a fictional term. There is no recognized protozoan class by this name.

This option is correct because 'Sporozoa' is a class of protozoans that are entirely parasitic. Members of this class lack traditional locomotor structures and reproduce via spores.