题目选项分析

Which of the following, if true, most logically completes the reasoning in the passage?

Kernland's government restricts the export of unprocessed cashew nuts in order to ensure a low-cost supply for domestic processing plants. Though the policy constrains farm income and limits the number of farmers who can profitably grow cashews, the government defends it on the grounds that, since the processing plants are in urban areas, removing the restrictions would hurt efforts to reduce urban unemployment. However, the policy may actually have contributed to urban unemployment, since __________.

【选项】the income earned by workers in the processing plants is generally greater than that earned by agricultural laborers in rural areas