Statement (i) is true: The First Five Year Plan (1951-1956) laid stress on agriculture, irrigation, and power projects to boost farm output and lay the foundation for industrial growth. Statement (ii) is true: The plan was based on the Harrod-Domar model, which emphasized the role of savings and investment in economic growth. It was adapted to Indian conditions. Statement (iii) is false: The Second Five Year Plan (1956-1961) was based on the Mahalanobis model, which focused on rapid industrialization, particularly the development of heavy industries.