Which one of the following orga- nisms is responsible for sleeping sicken?

Sleeping sickness, also known as Human African Trypanosomiasis (HAT), is caused by microscopic parasites of the genus Trypanosoma [2]. Specifically, the disease is caused by two subspecies of Trypanosoma brucei: T. b. gambiense (prevalent in West and Central Africa) and T. b. rhodesiense (found in East and Southern Africa) [3]. These protozoan parasites are transmitted to humans through the bite of an infected tsetse fly (Glossina species) [1]. While the disease primarily affects humans, it can also impact livestock, where it is known as 'ngana' [2]. Other organisms mentioned in the options, such as Leishmania (misspelled as Grishmania) and Ascaris, cause leishmaniasis and ascariasis respectively, but are not responsible for sleeping sickness [4]. If left untreated, the trypanosome infection eventually invades the central nervous system, leading to the characteristic sleep disturbances and potential death [3].

Sources

1. [1] https://www.cdc.gov/sleeping-sickness/about/index.html
2. [2] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 17: The Savanna or Sudan Climate > Problems, Prospects and Development of the savanna > p. 170
3. [3] https://www.ncbi.nlm.nih.gov/books/NBK535413/
4. [4] https://pmc.ncbi.nlm.nih.gov/articles/PMC126866/