[求教]大全section I-3 的A选项（之前没有讨论过）

3.    Economies in which a high percentage of resources are invested in research and development show greater growth in the long run than do those in which resources are channeled into consumption. Japanese workers spend a higher percentage of their income investing in research and development than do American workers.

To grow as fast as Japan has in the past three decades, the United States must change the tax code in order to encourage savings and investment and discourage debt.

Which of the following, if true, tends to weaken the argument?

(A) Japanese research is more focused on consumers than is research by American firms.

(B) Class mobility, highly valued in American culture, is encouraged by a growing rather than a stagnant economy.

(C) Studies have shown that countries with high consumption rates prosper in the short run.

(D) Proposed changes to the tax code could involve strict limits on the deductability of interest, and increased allowance for research.    

(E) Because a decreasing percentage of the United States is under 40, an age when savings are traditionally low, the savings rate will increase without changes to the tax code.
            

答案：E

为什么A不对？如果说日本的研究投资都是由消费者负担，而美国的都由公司负担的话，那么改变美国的税法只是改变美国消费者的存款量，却不增加美国公司的存款量，那么研究投资照样无法得到增长，那么结论must change the tax code"不就没用了吗？