Final answer:
The biological vector for African sleeping sickness is the Tsetse fly, responsible for transmitting Trypanosoma brucei to humans. Hence, option (a) is correct.
Step-by-step explanation:
The biological vector for African sleeping sickness is (a) Tsetse fly. African sleeping sickness, also known as trypanosomiasis, is caused by the hemoflagellate Trypanosoma brucei. There are two subspecies responsible for the disease in humans: Trypanosoma brucei rhodesiense causes East African trypanosomiasis (EAT), and Trypanosoma brucei gambiense causes West African trypanosomiasis (WAT).
The tsetse fly (Glossina spp.) is the insect that transmits these parasites to humans. Unlike malaria, which is transmitted by the mosquito, trypanosomiasis is specifically spread through the bite of the infected tsetse fly.
The symptoms of this disease include hemolymphatic stage and neurological stage. In the former, fever, headache, joint and muscle pain, swollen lymph nodes, and fatigue and weakness are seen, and in the latter stage, sleep disturbances, mental changes, tremors, and muscle rigidity, followed by seizures and coma are seen.