The aims of watershed management

Which of the following are the aims of watershed management ?

1. Soil and water conservation
2. Decrease the biomass production
3. Mitigation of droughts and floods
4. Increase the life of the downstream dams and reservoirs

1.  II and III only
2.  I, III and IV
3.  III and IV only
4.  I, II and IV 

Answer

B - I, III and IV