单选题 Economist: In order to decide what to do about protecting the ozone layer, we must determine the monetary amount of the economic resources that we would willingly expend to protect it. Such a determination amounts to a calculation of the monetary value of the ozone layer.
Environmentalists argue that the ozone layer does not have a calculable monetary value. However, we would not willingly expend an amount equal to all of the world's economic resources to protect the ozone layer, so the ozone layer is demonstrably worth less than that amount. Thus, the ozone layer has a calculable monetary value.
The reasoning in the economist's argument is flawed in that the argument

A、 uses evidence that the monetary value of a particular natural resource is less than a certain amount in order to establish that the monetary value of any natural resource is less than that amount.
B、 presupposes that the ozone layer should not be protected and then argues to that claim as a conclusion.
C、 takes advantage of an ambiguity in the term "value" to deflect the environmentalists charge.
D、 gives no reason for thinking that merely establishing an upper limit on a certain monetary value would allow the calculation of that monetary value.
E、 (E) does not directly address the argument of the environmentalists.

【正确答案】 D

【答案解析】[解析] 经济学家只是证明了臭氧层的货币价值存在一个上限，就驳斥了环境学家认为臭氧层的货币价值是不可预测的理论。很显然经济学家在没有给出确定了某物的货币价值上限就可预测那个货币价值是多少的根据，因此(D)是正确答案。