Final answer:
Soil becomes enriched during soil formation through weathering, decomposition of organic material, and additions from rain and dust. Erosion and leaching can remove nutrients from the soil. correct answer is d.
Step-by-step explanation:
Soil becomes enriched during soil formation through a combination of processes. Weathering of soil minerals into components that dissolve, decomposition of organic material into components that can dissolve in the soil solution, and additions from rain, snowfall, and dust all contribute to the enrichment of soil.
On the other hand, erosion and leaching can remove nutrients from the soil. Therefore, the correct answer is d. all of the above.