Record companies defend their substitution of laser-read compact discs (CD’s) for the much less expensive traditional long-playing vinyl records in their catalogs by claiming that the audio market is ruled by consumer demand for ever-improved sound reproduction rather than by record manufacturers’ profit-motivated marketing decisions. But this claim cannot be true, because if it were true, then digital audiotape, which produces even better sound than CD’s, would be commercially available from these same record companies, but it
13. Which of the following, if true, would most strengthen the argument against the record companies’ claim?
(A) When CD’s were first introduced in the audio-reproduction market, prices were high and selection was poor.
(B) Record companies are reluctant to attempt commercial production of digital audiotape until profits from the sales of CD’s have enabled them to recover their investments in compact-disc manufacturing technology.
(C) Some CD’s have been so much in demand that consumers have experienced long delays in obtaining copies.
(D) Because CD’s work according to principles very different from those that govern conventional recordings, commercial production of CD’s requires new kinds of manufacturing technology.（B）
(E) Any valid comparison of CD audio reproductions to digital audiotape reproductions must be based on identical performances played back on the highest quality disc or tape player.
is not.
请教问题中strengthen the argument against the record companies’ claim?是加强还是反对? | 
