The correct answer is C) Aksum.
In the 1300s and 1400s, the city-state that became the wealthiest and most powerful of East Africa's coastal region was Aksum.
One of the most important kingdoms in ancient Africa was the Aksum empire. It existed from the first century to the 8th CE, and they inhabited the territories of what now is Sudan, Ethiopia, and years later Aksum spread through Yemen and South Arabia. They developed a trade that none other empires of its time and created a great navy that navigated the Nile River and the Red Sea to protect its trade routes.