Explanation:

1, 2, 3, and 4

73rd Amendment Act (1992): This amendment provided for constitutional recognition of Panchayati Raj institutions and sought to strengthen local self-government. It aligns with the Directive Principles that emphasize decentralization of power and grassroots democracy.

Abolition of Zamindari System: The abolition of the zamindari system aimed to remove intermediaries between the state and the actual cultivators, thus ensuring equitable distribution of land and resources, which corresponds with the goal of social justice as outlined in the Directive Principles.

Minimum Wages Act (1948): The Minimum Wages Act ensures that workers receive fair wages, which is in line with the Directive Principles that mandate the state to ensure just and humane conditions of work and a living wage for workers.

Abolition of Privy Purses (1971): This initiative abolished the privileges and financial allowances granted to former rulers of princely states, aiming to promote equality and social justice, which are central to the Directive Principles.

Therefore, all the initiatives listed contribute to the implementation of the Directive Principles. Hence, the correct option is 4. 1, 2, 3, and 4