Indian Ocean trade reached far inland and led to rise of important, wealthy states in Central and Southern Africa

The above statement is True.

Explanation:

As the trade especially between Asia and Africa garnered momentum, certain states became the better for it. That list of city-states includes but are not limited to the following: Sofala, Mombasa, Kilwa, Malindi, etc.

Of very great interest to the Asians were the gold, iron, ivory. etc. The Africans on the other hand were willing to export the above in exchange for ceramic objects, silk, and other items that were not native to those parts of Africa. The Africans paid heavily for these things because they had them in large qualities nor did they have the know-how to manufacture them.

Another important phenomenon that occurred during these times were interracial marriages. This exactly was how the Swahili people were formed.

Cheers

the first part is ocean

explanation:

the answer to your question is,

old stone age.

-mabel < 3