Which one is not a Directive Principle?

Article 39 lays down certain principles of policy to be followed by the State, including providing an adequate means of livelihood for all citizens, equal pay for equal work for men and women, proper working conditions, reduction of the concentration of wealth and means of production from the hands of a few, and distribution of community resources to subserve the common good. Article 48 of the Constitution of India mandates the state to prohibit the slaughter of cows and calves and other milch and draught cattle. The State, according to Article 51, must also strive for the promotion of international peace and security, and Parliament has been empowered under Article 253 to make laws giving effect to international treaties. Prohibition of cow slaughter is a Directive Principles of State Policy contained in Article 48 of the Constitution.