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

The correct option is Participation of workers in the management of industries.

Explanation:

The Directive Principles of State Policy (DPSP) contained in Part IV of the Constitution of India aim to establish social and economic democracy.

The 42nd Constitutional Amendment Act of 1976 added four new Directive Principles to the original list:

1. Article 39: To secure opportunities for the healthy development of children.

2. Article 39A: To promote equal justice and to provide free legal aid to the poor.

3. Article 43A: To take steps to secure the participation of workers in the management of undertakings, establishments, or other organizations engaged in any industry.

4. Article 48A: To protect and improve the environment and to safeguard forests and wildlife.

Among the given options, "Participation of workers in the management of industries" (Article 43A) was added by the 42nd Amendment Act, 1976.