关于XDF讲义中的一道题请教大家

14(Z). Three large companies and seven small companies currently manufacture a product with potential military applications. If the government regulates the industry, it will institute a single set of manufacturing specifications to which all ten companies will have to adhere. In this case, therefore, since none of the seven small companies can afford to convert their production lines to a new set of manufacturing specifications, only the three large companies will be able to remain in business.

Which of the following is an assumption on which the author’s argument relies?

A. None of the three large companies will go out of business if the government does not regulate the manufacture of the product.
B. It would cost more to convert the production lines of the small companies to a new set of manufacturing specifications than it would to convert the production lines of the large companies.
C. Industry lobbyists will be unable to dissuade the government from regulating the industry.
D. Assembly of the product produced according to government manufacturing specifications would be more complex than current assembly procedures.
E. None of the seven small companies currently manufactures the product to a set of specifications that would match those the government would institute if the industry were to be regulated.
为什么答案是E 虽然阅读后根据意思明白了但寒假在XDF上课时说出现none的选项是要先降位的而且这道题目上课时讲过中文版当时是将NONE翻译为了否定的意思而假设题答案多为否定句那么当出现NONE是到底是首先降位还是当否定句啊？？？？很疑惑