[讨论]完整填写句子题，求助求助！！

icyeye

（XDF）49

Sales campaigns aimed at the faltering personal computer market have strongly emphasized ease of use, called user-friendliness. This emphasis is oddly premature and irrelevant in the eye of most potential buyers, who are trying to address the logically prior issue of whether_________

(c) currently available models are user-friendly enough to suit them. (为什么错？)

(e) they have enough sensible uses for a personal computer to justify the expense of buying one. (为什么对？)