a. The Right to Equality

b. The Directive Principles of State Policy

c. The Right to Freedom

d. The Concept of Welfare

Answer- b

Explanation:

Article- 39 of Part- IV (DPSPs), as amended by the 42nd Constitutional Amendment, 1976, directs the state policy at securing: 

(a) the citizens, men and women equally, have the right to an adequate means of livelihood; 

(b) the ownership and control of the material resources of the community are so distributed as best to subserve the common good; 

(c) the operation of the economic system does not result in the concentration of wealth and means of production to the common detriment;  

(d) there is equal pay for equal work for both men and women; 

(e)the health and strength of workers, men and women, and the tender age of children are not abused and that citizens are not forced by economic necessity to enter avocations unsuited to their age or strength;

(f) children are given opportunities and facilities to develop in a healthy manner and in conditions of freedom and dignity and that childhood and youth are protected against exploitation and against moral and material abandonment. 

Hence, option b is correct.

Read: Previous Year UPSC Polity Questions (PYQs) With Explanation 2021