The West African Inland Niger Delta Grew into the Urbanized

The West African inland Niger delta grew into the urbanized chiefdom of Jenné-jeno ___________

A) Due to its extensive trade networks with Meroë and Aksum.
B) Because it was threatened with attack from Bantu warriors from the Great Lakes region.
C) After a shift in monsoon rain patterns shrank the Sahara Desert and led to land reclamation.
D) With limited external interactions with other populations.