During the Green Revolution, the most recent technological innovations that were widely employed in less developed countries primarily included:
- Seed hybrids and animal breeds
- Chemical fertilizers and pesticides
- Irrigated farm fields
Among these, "seed hybrids" and "chemical fertilizers and pesticides" are often considered the hallmark innovations of the Green Revolution that significantly contributed to increasing agricultural productivity in less developed countries.
If you are looking for the best fit among the options provided for what characterized the technological advancements during the Green Revolution, Seed hybrids and animal breeds and Chemical fertilizers and pesticides would likely be the most accurate choices.
Therefore, the answer would be:
Seed hybrids and animal breeds OR Chemical fertilizers and pesticides (either of these can be seen as key innovations)