B is the best option.
The incomplete passage calls for an explanation of why price-reduction and massmarketing methods should not be used for premium products. B, which states that sales of these products require that they appear specials, provides such an
explanation. Therefore, B is the best answer. No other choice offers an appropriate explanation. The diminishing proportion of affluent buyers cited in A argues for using price reductions to attract buyers of lesser means. C suggests that purchasers of premium products find reduced prices attractive, and it has not been established that the methods affect quality or perception of quality. D argues for, rather than against, using mass marketing. E is inappropriate, since there is no indication that manufacturing costs are relevant.