单选题 For the safety-conscious Swedish market, a United States manufacturer of desktop computers developed a special display screen that produces a much weaker electromagnetic field surrounding the user than do ordinary screens. Despite an advantage in this respect over its competitors, the manufacturer is introducing the screen into the United States market without advertising it as a safety improvement.
Which of the following, if true, provides a rationale for the manufacturer's approach to advertising the screen in the United States?

A、 Many more desktop computers are sold each year in the United States market than are sold in the Swedish market.
B、 The manufacturer does not want its competitors to become aware of the means by which the company has achieved this advance in technology.
C、 Most business and scientific purchasers of desktop computers expect to replace such equipment eventually as better technology becomes available on the market.
D、 An emphasis on the comparative safety of the new screen would call into question the safety of the many screens the manufacturer has already sold in the United States.
E、 (E) Concern has been expressed in the United States over the health effects of the large electromagnetic fields surrounding electric power lines.

【正确答案】 D

【答案解析】[解析] 本题属于“解释”题型，答案要满足“直接、无推导”原则。(D)说明强调优势会对其已在美国销售的屏幕安全性提出质疑，解释了该制造商并未宣扬其优势的原因；(B)易误选，但段落里面并未告诉我们广告中一旦说出这种优点竞争者就知道，因此不能对结论提供一个很好的解释，所以(B)不对。