I believe the answer would be B
The correct answer is D)to unite people of African descent around the world
Pan-Africanism was about uniting people who have African heritage all throughout the world, regardless of their current place of residence.
IRRIGATION DITCHES WERE USED TO PREVENT THE RIVER FROM FLOODING
Communism
This is an example of central planning in which everything is directed by the government. These types of economies tend not to do well because as the question states the incentive for individuals is taken away.