Which agricultural innovation became more common by the end of the Middle Ages?

The choice of windmills and advanced plows as the correct answer is significant because it highlights the technological advancements that occurred in agriculture by the end of the Middle Ages. Windmills represented a key innovation in harnessing natural energy for tasks like grinding grain, thereby increasing efficiency in food production. The introduction of advanced plows, particularly the heavy iron plow with a moldboard, allowed for deeper tilling of heavier soils, which significantly improved crop yields. These innovations collectively contributed to agricultural productivity, which was crucial for supporting the growing population and facilitating trade in the later Middle Ages.

In contrast, hand plowing techniques were limited in their effectiveness compared to the advancements made during this period. While livestock herding methods certainly evolved, they did not have the transformative impact on arable farming that windmill and plow technologies did. Monoculture farming practices may have existed, but they were not as widespread or as significant as the impact of windmills and advanced plows on agricultural systems of the time. Thus, the technological advancements represented by windmills and advanced plows stand out as pivotal developments at the close of the Middle Ages.