题目选项分析

Cocoa grown organically on trees within the shade of the rain forest canopy commands a premium price. However, acquiring and maintaining the certification that allows the crop to be sold as organically grown is very time-consuming and laborious. Meanwhile, the price premium for the grower is about 30 percent, whereas cocoa trees grown in full sun using standard techniques can have twice the yield of organic, shade-grown trees.Financially, therefore, standard techniques are the better choice for the farmer.

Which of the following,if true, most seriously weakens the arguement?

【选项】Cocoa is not the only cash crop that can be raised on plots that leave the rain forest canopy overhead essentially intact.