Which of the following article of Indian constitution is related with the declaration of a welfare state?

Article-36 to 51 under Part-IV of constitution provides for Directive Principles of State Policy. It is a set of philosophy to make India into a welfare state. Article-39 contains certain principles of policy which are to be followed by the state. These include adequate means of livelihood to men and women equally equal pay for equal work to both men and women and healthy environment for children to develop etc.