In darfur, peacekeeping efforts by other african nations have succeeded led to war between other nations failed caused further suffering

The correct answer is - failed.
The African nations with their peacekeeping efforts completely failed in their mission in Sudan. They did not managed to keep the peace at all, and everything continued as if they were not present on the terrain. The mission lasted for around three years, from 2004 till 2007, and after the United Nations saw that there's no effect from it, the AMIS (as it was called) was replaced by UNAMID, peacekeeping forces from the United Nations.

Ba population changes in response to a change in environment

Bwould be my guess |-/