runoff of water. erosion of sand dunes. compaction of rock layers. decomposition of plants and animals.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Soil texture is improved by
Possibilities:
- runoff of water.
- erosion of sand dunes.
- compaction of rock layers.
- decomposition of plants and animals.

decomposition of plants and animals.