The correct answer is option 4, the Irish Constitution. The Directive Principles of State Policy is a set of guidelines and principles given in Part IV of the Indian Constitution. These principles are not enforceable by any court but are meant to guide the state in policy-making and governance. They include provisions for social justice, economic welfare, international peace, and more. The concept of Directive Principles of State Policy was borrowed from the Irish Constitution, which was adopted in 1937. The Irish Constitution was the first written constitution to include such principles, and the framers of the Indian Constitution found it to be a valuable addition. Therefore, the Indian Constitution adopted the Directive Principles of State Policy from the Irish Constitution.