Explanation:

- The Industrial Policy Resolution (IPR) of 1956 laid a strong framework for the national economy.

- It emphasized the importance of the public sector and aimed to reduce income inequalities.

- The correct answer is the Second Five Year Plan since IPR 1956 was fundamental to its strategies.

- The First Five Year Plan (Option 3) mainly focused on agriculture and irrigation.

- The Third Five Year Plan (Option 1) emphasized self-reliance and the development of heavy industries.

- The Fourth Five Year Plan (Option 2) tackled issues related to economic growth, stability, and social justice through balanced regional growth.