Loss of minerals due to farming. Deserts forming due to tree cutting. Flooding due to dam construction. Minerals washing out due to heavy rain.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which of these soil changes is due only to natural causes?
Possibilities:
- Loss of minerals due to farming.
- Deserts forming due to tree cutting.
- Flooding due to dam construction.
- Minerals washing out due to heavy rain.

Minerals washing out due to heavy rain.