Which principle among the following was added to the Directive Principles of State Policy by the 42nd Amendment to the Constitution? [2017]

Which principle among the following was added to the Directive Principles of State Policy by the 42^nd Amendment to the Constitution?

The 42nd Amendment Act of 1976 added four new Directive Principles to the original list. They require the State:
1. To secure opportunities for healthy development of children (Article 39).
2. To promote equal justice and to provide free legal aid to the poor (Article 39 A).
3. To take steps to secure the participation of workers in the management of industries (Article 43 A).
4. To protect and improve the environment and to safeguard forests and wild life (Article 48 A).

The 44th Amendment Act of 1978 added one more Directive Principle, which requires the State to minimise inequalities in income, status, facilities and opportunities (Article 38).
The 86th Amendment Act of 2002 changed the subject matter of Article 45 and made elementary education a fundamental right under Article 21A. The amended directive requires the State to provide early childhood care and education for all children until they complete the age of six years.
The 97th Amendment Act of 2011 added a new Directive Principle relating to cooperative societies. It requires the state to promote voluntary formation, autonomous functioning, democratic control and professional management of co-operative societies (Article 43B).