According to economists studying India, Pakistan, the Philippines, and Mexico, which factors were essential for foodgrain production to keep pace with population growth over the past forty years?

Explanation

The four critical elements are: I - advanced high-yield seed varieties; II - use of fertilizers, pesticides, and irrigation; III - enhanced transportation systems; and IV - improved agricultural extension services. Without all these components combined, foodgrain production would not have matched the population increase in these countries.