题目选项分析

Because of a rare type of fungus that killed off many cacao trees in Brazil, there was an unusually meager harvest of cacao beans this year. The wholesale price of cocoa solids and cocoa butter has increased significantly and is unlikely to fall in the foreseeable future. As a result, the retail price of chocolate is certain to increase within six months.

Which of the following, if true, most seriously weakens the argument above?

【选项】Researchers have discovered an effective method to kill the fungus.