Correct Answer:
A. Deforestation
Deforestation is a primary cause of soil erosion. Trees and other vegetation play a critical role in anchoring soil with their root systems and protecting the ground from the direct impact of rain and wind. When forests are cleared, the soil becomes exposed and loses its structural integrity, making it highly susceptible to being washed away by water or blown away by wind.
- B: Residual is incorrect; 'residual' refers to what remains after a process, not a cause of erosion.
- C: Mining can cause localized erosion, but deforestation is a more widespread and significant contributor to general soil erosion across landscapes.
- D: Leaching is incorrect; leaching is the process where water dissolves and carries away nutrients from the soil, not the physical removal of soil particles itself, which is erosion.