Despite sky-high expectations, the global market for kale has remained stagnant for the last five years. However, although retail prices and the amount of kale produced have likewise varied little during the same period, kale farmers have increased their profits by 15 percent over the last two years.
Any of the following statements, if true about the last two years, helps to explain the rise in profits EXCEPT:
【选项】
Kale farmers adopted a new machine that more efficiently harvests the crop, allowing them to save money on labor costs.
选项是否正确？