Concept:The relocation of the Kanem-Borno Empire's capital was caused by environmental pressures in the original region.
Explanation:The empire originally centered its power in Kanem, east of Lake Chad.
Over time, the area experienced severe environmental degradation.
This made farming and settlement increasingly difficult for the people.
Borno, located west of Lake Chad, offered better water supply and more fertile land.
These improved conditions made Borno more suitable for agriculture and stable living.
Therefore, the shift from Kanem to Borno was primarily an environmental adaptation.
Answer:A. Environmental changes.