(d) Plasmodium
Plasmodium (the malarial parasite) divides into many daughter cells simultaneously through multiple fission.
The passage explicitly states: "Other single-celled organisms, such as the malarial parasite, Plasmodium, divide into many daughter cells simultaneously by multiple fission." Yeast reproduces by budding; Leishmania and Amoeba undergo binary fission. Examiners expect students to distinguish between binary fission, multiple fission, and budding.