(d) : Wuchereria bancrofti is a parasitic filarial nematode worm spread by a mosquito vector. It is one of the three parasites that cause lymphatic filariasis. Elephantiasis can result if the infection is left untreated. Limited treatment modalities exist and no vaccines have been developed. Malaria is caused by protozoan parasites of the genus Plasmodium. Malaria parasites are transmitted by female Anopheles mosquitoes. Sleeping sickness or African trypanosomiasis is a parasific disease in people and animals, caused by protozoa of genus Trypanosoma and transmitted by the tsetse fly. Kala-azar is caused by Leishmania (protozoan) and is transmitted by sand fly.