单选题 Electrical engineers have repeatedly demonstrated that the best solid-state amplifiers are indistinguishable from the best vacuum-tube amplifiers with respect to the characteristics commonly measured in evaluating the quality of an amplifier's musical reproduction. Therefore, those music lovers who insist that recorded music sounds better when played with the best vacuum-tube amplifier than when played with the best solid-state amplifier must be imagining the difference in quality that they claim to bear.
Which one of the following, if true, most seriously weakens the argument?

A、 Many people cannot tell from listening to it whether a recording is being played with a very good solid-state amplifier or a very good vacuum-tube amplifier.
B、 The range of variation with respect to the quality of musical reproduction is greater for vacuum-tube amplifiers than for solid-state amplifiers.
C、 Some of the characteristics that are important in determining how music sounds to a listener cannot be measured.
D、 Solid-state amplifiers are more compact, use less power, and generate less heat than vacuum-tube amplifiers that produce a comparable volume of sound.
E、 (E) Some vacuum-tube amplifiers are clearly superior to some solid-state amplifiers with respect to the characteristics commonly measured in the laboratory to evaluate the quality of an amplifier's musical reproduction.

【正确答案】 C

【答案解析】[解析] 本题根据两种扩音机在音乐再现方面的性能一样，做出了音乐爱好者们认为的性能差异是经他们主观臆测而得出来的结论。要削弱结论，只要削弱前提即可。选项(C)通过找他因的方法对本题的辩论的前提进行了削弱，因此(C)为正确答案。