OG11紫皮-10实在想不通啊

10．Which of the following best completes the passage below?

At a recent conference on environmental threats to the Noah Sea，most participating countries favored uniform controls on the quality of effluents，whether or not specific environmental damage could be attributed to a particular source of effluent．What must, of course, be shown, in order to avoid excessively restrictive controls，is that    ．

(A)  any uniform controls that are adopted are likely to be implemented without delay

(B)  any substance to be made subject to controls can actually cause environmental damage

(C)  the countries favoring uniform controls are those generating the largest quantities of effluents

(D)  all of any given pollutant that is to be controlled actually reaches the North Sea at present

(E)  environmental damage already inflicted on the North Sea is reversible

B没有疑问，但是D为何不对呢？只控制那些到North Sea的pollutant，不正是避免控制过度吗？特别是OG的解释更是让人看不懂，请看懂了的高人们指点一下！想了一个晚上，真是怎么都想不出个头绪来。

D  It is not necessary to prove that all of a pollutant reaches the North Sea．It is necessary to prove only that some of it does．

发现就是OG10-62，一个古董难题，论坛里可以搜到经典解答。不好意思，请版主删掉此贴吧。