Which of the following are responsible for soil degradation?
1. Soil erosion
2. Desertification
3. Mulching
4. Salinization
Select the correct answer from the code given below.
1
1,2 and 3 only
2
1 and 2 only
3
1, 2 and 4 only
4
1, 2, 3 and 4
5
None of the above