A large group of parasitic protozoa, some of which causes various diseases such as malaria to humans, are:

Explanation

Explanation:A large group of parasitic protozoa, some of which causes various diseases such as malaria to humans, are Apicomplexans.Annelids are a phylum of segmented worms that included earthworms, leeches, and various marine worms. They are not parasitic protozoa. Platyhelminthes are a phylum of worms that includes many parasitic species, such as tapeworms and flukes. However, they are not protozoa. Arthropods are a phylum of joint-legged invertebrates that includes insects, spiders, and crustaceans. They are not protozoa, although some Arthropods can be vectors for protozoan diseases (such as mosquitoes and malaria).