Statement 1 is indeed incorrect. The demographic dividend refers to the increase in the share of the working-age population in the total population of a country, and it is not inherently related to illiteracy. While education helps in reaping the benefits of demographic dividend, it does not guarantee the elimination of illiteracy. Therefore, this statement cannot be accepted as invariably true.

Statement 2 is correct. The passage mentions that the relative ratio of the very young and very old will decline for a while, indicating an increase in the relative ratio of the elderly and children. Thus, this statement is accurate.

Statement 3 is incorrect. There is no indication in the passage regarding the stabilization of population growth, nor can we make assumptions about the speed of such stabilization. Therefore, we cannot confirm the facts stated in this statement.

Since only statement 2 is correct, option (b) is the most appropriate answer.