Which of these is/are flood prevention and mitigation strategy?
1. Construction of flood protection embankments
2. Depopulating the flood plains
3. Afforestation
4. Decongesting river channels
Select the correct option using the codes given below
1 and 2 only
1, 2 and 3 only
2, 3 and 4 only
1, 2, 3 and 4