Concept:Afforestation in dry West African areas mainly helps fight desertification by acting as a barrier against dry winds and moving sand.
Explanation:In arid regions, dry winds and drifting sand destroy farmland and settlements.
Trees planted through afforestation act as windbreaks, reducing wind speed at ground level.
This checks the southward spread of the Sahara, allowing soil and moisture to be retained.
While forests also support wildlife, timber, and taungya systems, those are not the primary aim in arid zones.
The urgent need is to protect the land from desert encroachment caused by wind erosion.
Answer:B. serve as windbreak to check desert encroachment.