Answer:
Swahili and Kilwa
Explanation:
East Africa coasts played an influential role in promoting trade with Asia through the Indian Ocean to places like India, Southeast Asia, and China. As trade increase between Africa and Asia, city-states flourished and prospered along the eastern coast of Africa. These included Kilwa, Mombasa, Malindi, Sofala, and others.
Trade increased in East Africa because of gold and ivory. Muslim traders from Arabia brought luxury goods in Africa.
Many merchants from Arabia and Asia stayed in the city-states of East Africa, which led to a new and different ethnic group known as the Swahili. Swahili, steadily grew and prospered, and become economic power by the 1400s.
