Which of the following concepts are relatable to the income of members of the public while considering public welfare?
1. Sensitivity of demand
2. Elasticity of demand
3. Sensitivity of expenditure
4. Elasticity of expenditure
Select the correct answer using the code given below.
1
1 and 2 only
2
2 and 3 only
3
3 and 4 only
4
1 and 4 only