Explanation:

Economic Survey says that the "basic needs" approach to economic development focuses on minimum specified quantities of basic necessities such as food, clothing, shelter, water and sanitation that are necessary to prevent ill health and undernourishment.

• The Bare Necessities Index (BNI) is an attempt to quantify this approach to economic development using data from the National Statistical Office (NSO). It is created for all States/Union Territories by employing data at State Level.
• Economic Survey 2020-21 constructs a Bare Necessities Index (BNI) at the rural, urban and all India level. The BNI summarises 26 indicators on five dimensions viz., water, sanitation, housing, micro-environment, and other facilities. 
• The BNI has been created for all States for 2012 and 2018 using data from two NSO rounds viz 69th and 76th on Drinking Water, Sanitation, Hygiene and Housing Condition in India. 

Improvement in Bare Necessities

• Bare necessities have improved across all States in the country in 2018 as compared to 2012. 
• Increase in equity is noteworthy as the rich can access private options for public goods.

Hence only statements 2&3 are correct.