The correct option is B Plasmodium
Malaria is a disease caused by a parasite called Plasmodium. Malaria and filariasis still continue to pose public health problems in developing countries of the tropics. Human malaria has been known to be caused by four Plasmodium species namely P. falciparum, P. vivax, P. malariae, and P. ovale.
Aedes mosquito causes Dengue fever, Wuchereria causes filariasis, and typhoid occurs by Salmonella typhi bacteria.
So, the correct answer is- plasmodium.