求解释移到GMAT逻辑题

freewing777

A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants. Agronomists studying the growth of this herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert. Hence, the herb’s high histidine production must be the key feature that allows it to grow in metal-rich soils.
In evaluating the argument, it would be most important to determine which of the following?
A. Whether the herb can thrive in soil that does not have high concentrations of the toxic metals
B. Whether others of the closely related group of plants also produce histidine in large quantities
C. Whether the herb’s high level of histidine production is associated with an unusually low level of production of some other amino acid
D. Whether growing the herb in soil with high concentrations of the metals will, over time, reduce their concentrations in the soil
E. Whether the concentration of histidine in the growing herb declines as the plant approaches maturity
这个题答案给的是B，我选的是E，想请教一下各位大神，为什么E不对呢？如果随着herb的长大，H的含量在减少，那就很可能不是因为H原因而得以生存；但是如果H含量不随着plant的成熟而减少，那就是有可能是因为H的原因。这样的推理错在哪里呢？还有B选项，别的plants的情况就可以推断herb的情况吗？
求解答，谢谢啦！

Fiona09

传送给楼主：https://gmat.la/question/OG2016-CR-100

ai559031

一開頭就說同類的植物（a group of closely related plants that ）都可以在有毒的土裡利用Ｈ抗毒

所以Ｂ選項說others of the closely related group of plants也可產生Ｈ; 則代表她們是依靠Ｈ抗毒
反之, 若其他同類植物不能產生Ｈ, 就代表這種類型植物抗毒的原因不是Ｈ,而是另有他因

E選項說成長過程中histidine的量變多或變少，這跟大量的histidne殺毒與否沒有直接關係