Land Degradation

Correct answer: A. Land degradation

The governing concept is land degradation caused by removal of protective vegetation. When too many animals graze an area for too long, grasses and small plants cannot regenerate. The exposed soil is then more easily removed by wind and running water, while trampling can compact the surface and reduce infiltration. These processes lower land productivity and may contribute to desertification. Consequently, option A is correct. Permanent improvement in soil fertility is not expected from excessive grazing; glacier expansion and reduced ocean salinity are unrelated physical processes. A useful chain for examination is overgrazing → vegetation loss → soil exposure and erosion → land degradation.