(a) Soil Settlement
(b) Consolidation
(c) Soil Erosion
(d) Population
Ans. (c) : Soil Erosion

Explanation:-
Soil erosion is the detachment, transport, and deposition of soil particles on land surface. It is also called loss of soil.
Various methods for preventing and reducing soil erosion are –
(a) Plantation of trees and plants
(b) Prevention of deforestation
(c) Preventing excessive grazing.