Q: 49 (NDA-I/2015)

A farmer in a semi-arid area claims that his farming practice is very environment friendly.
Which of the following practices on his farm can justify his claim ?
1. Planting a tree belt.
2. Practising crop rotation.
3. Carrying out a large scale irrigation system.
4. Using organic fertilizers.
Select the correct answer using the code given below :
question_subject: 
Geography
question_year: 
2015
question_exam: 
NDA-I
stats: 
0,1824,592,136,1904,240,136