题目选项分析

Most of AmTrans' weekly trains travel to and from Harcourt Terminal, a heavily trafficked train station. AmTrans depends for its success on running trains in all types of weather and punctual arrivals, and is consequently planning to replace half of its current trains with bullet trains, which can operate regardless of weather conditions and which can travel at twice the speed of AmTrans' current trains.

Which of the following, if true, could present the most serious disadvantage for AmTrans in replacing its current trains with bullet trains?

【选项】The cost of manufacturing AmTrans' current trains so that they could travel at twice the speed they currently do is expected to decline over the next several years.