The correct answer is Northern Africa.
Explanation
The Nile River is the most important river in Africa and the second longest river in the world with 6853 km that covers 10 countries: Burundi, Rwanda, Tanzania, Uganda, Kenya, the Democratic Republic of the Congo, South Sudan, Sudan, Egypt and Ethiopia and finally flows into the Mediterranean sea through a delta where are placed the most important cities of Egypt: Alexandria and Cairo.
In the Ancient time, Egypt was a fluvial civilization located in the Northern Africa next to the Nile river that was the most important resource for the economy and lifestyle, considering that was the main way of transport and therefore of trade. Also, it made that the ground was fertile for agriculture. So, the correct answer is B. Northern Africa.
