题目选项分析

In a certain rural area, people normally dispose of household garbage by burning it. Burning household garbage releases toxic chemicals known as dioxins. New conservation regulations will require a major reduction in packaging—specifically, paper and cardboard packaging—for products sold in the area. Since such packaging materials contain dioxins, one result of the implementation of the new regulations will surely be a reduction in dioxin pollution in the area.

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

【选项】It is not known whether the dioxins released by the burning of household garbage have been the cause of any serious health problems.