During the 19th century, the powerful nations of Europe "carved up" Africa into colonies and territories. Before colonization, how were the borders in Africa established?

A)Borders were formed by rivers, mountains and other geographic features.

B)Borders were determined by allegiance to a central leader or a community.

C)Borders generally did not exist before the colonization of Africa.

D)Borders were maintained by military leaders who worked to separate religious groups.