一道想不明白的逻辑题，拜托各位大牛们指点一下~~~

crystalwhite

The presence of microorganisms that produce a toxin cause sea water to turn brownish red, phenomenon known as a red ride. Sea otters do not feed in areas where clams, their main source of food, have become contaminated with this toxin. According to a proposed explanation of the otter’s behavior, the otters sample the clams in a potential feeding area and can taste any toxin in them.

Which of the following, if true, would most strongly indicate that the hypothesis described in the last sentence of the passage is not correct?

(A) In some of the area where red tides occur, neither clams nor sea otters are indigenous species.

(B) The presence of sea otters in a given area has a significant effect on which other marine organisms are to be found in that area.

(C) When seawater in an area unaffected by red tide is artificially dyed brownish red, sea otters do not feed on the clams in that area.

(D) If the clams in a given areas are contaminated with toxin, sea otters move to other areas in search of food.

(E) Although very small amounts of the toxin produced during a red tide are not harmful, large doses can be fatal to animals the size of sea otters.
我那份答案上写的是选D选项，可我总也想不通为什么，总觉得C选项似乎更有道理，哪位解开我心中的疑惑，感激不尽啊~~~

wangsiwei

我觉得也是C，说明是用眼睛看到的，不是尝到的。
D－－脱离了主题了吧，主题就是问为什么sea otter不吃clam了，D是不吃会到别的地方吃，和主题无关。
等待大牛。

loverwy

原文说的是“如果clam被污染了，sea otter就不会吃。解释是：sea otter 会先在某小区域内尝一下clam, 如果发现有毒，就不会去吃整个区域的clam.”

C说的是，现在把某海水区域人为地染成"brownish red", 发现sea otter也不吃clam.

因为人为地染成"brownish red" 是不含毒的，如果按照原文解释， sea otter尝了以后发现没毒，就会去吃clam. 但现在没吃，就说明原文的解释不成立。

即所谓的异因同果。

D说的是，如果某个海水区域的clam有毒，sea otter 就去其他地方吃了。这只是原文事实的进一步衍生，即不吃受污染区域的clam后，只能去其他地方觅食，不能削弱解释。