The correct option is C Plasmodium faciparum
Plasmodium vivax is a protozoal parasite and a human pathogen. It is less virulent than Plasmodium falciparum, the deadliest of the five.
Plasmodium berghei is a unicellular parasite (protozoan) that infects mammals other than humans.
Plasmodium yoelii is a parasite of the genus Plasmodium subgenus vinckela.
Plasmodium falciparum is a protozoan parasite, one of the species of the Plasmodium that causes malaria in humans. Malaria caused by this species is the most dangerous form of malaria.
So, the correct answer is option C.