56. Although custom prosthetic bone replacements produced through a new computer-aided design process will cost more than twice as much as ordinary replacements, custom replacements should still be cost-effective. Not only will surgery and recovery time be reduced, but custom replacements should last longer, thereby reducing the need for further hospital stays.

Which of the following must be studied in order to evaluate the argument presented above?

(A) The amount of time a patient spends in surgery versus the amount of time spent recovering from surgery

(B) The amount by which the cost of producing custom replacements has declined with the introduction of the new technique for producing them

(C)The degree to which the use of custom replacements is likely to reduce the need for repeat surgery when compared with the use of ordinary replacements

(D) The degree to which custom replacements produced with the new technique are more carefully manufactured than are ordinary replacements

(E) The amount by which custom replacements produced with the new technique will drop in cost as the production procedures become standardized and applicable on a larger scale

C说判断降低了二次手术

但文中没有提及有二次手术这一说啊，这是不是自己编出来的啊

再说文中只说由计算机设计的假肢虽然研发成本膏，但是还是划算的。因为它的时间更长，住院时间短。

没用任何一词提到二次手术啊

原文有提到的是"custom replacements should last longer". 而C就是在这里展开说custom replacements 的.就是在evaulate文章.

另外,文章是没有出现repeat surgery,选项里是可以出现原文没有说的东东.

选项里出现原文没有说的是可以的.