What factors contributed to the prosperity of the kingdom of nubia?

The best answer for this question would be the following:

Trade. The region that was located near the Nile river, had encourage the kingdom of nubia to trade with other countries such as Egypt and the Mediterranean world which had linked these two together.

Explanation:

Trade. The region that was located near the Nile river, had encourage the kingdom of nubia to trade with other countries such as Egypt and the Mediterranean world which had linked these two together.

what are the others?

answer; /// slavery should be outlawed in the new country, was part of the initial draft of the declaration of independence, but not part of the final