Explanation:

4th option is correct. 

Differential Rate of Interest Scheme (DRI)
The scheme was introduced in 1972 and is being implemented by all-Indian Scheduled Commercial Banks.
The important categories of borrowers under the scheme are SCs/STs and others engaged on a very modest scale, in agriculture and/or allied agricultural activities, people who themselves collect or do elementary process­ing of forest products, people physically engaged on modest scale in the fields of cottage and rural industries and vocation, indigent students of merit, etc.