Statement (i): Kanwar Sain conceptualized the Indira Gandhi Canal project in the early 1950s. However, its launch occurred in 1958, not 1961. Therefore, this statement is inaccurate.
Statement (ii): Canal irrigation introduced to the command areas of the Indira Gandhi Canal project has demonstrably transformed the agricultural economy, primarily through enhanced agricultural productivity. This statement is accurate.
Statement (iii): The expansion of canal irrigation in Rajasthan and adjacent regions has resulted in increased cultivated area and crop intensity, with a notable positive impact on water-reliant crops like rice and wheat. This statement is accurate.
Statement (iv): Water-intensive crops, including rice and wheat, have supplanted traditional arid-adapted crops such as jowar and bajra, owing to the increased availability of irrigation. This statement is also accurate.
Consequently, only statements (ii), (iii), and (iv) are accurate, identifying option (D) as the correct selection.