Which of the following most logically completes the argument?
Yorco and Zortech are two corporations that employ large numbers of full-time workers who are paid by the hour. Publicly available records indicate that Yorco employs roughly the same number of such hourly wage workers as Zortech does but spends a far higher total sum per year on wages for such workers. Therefore, hourly wages must be higher, on average, at Yorco than at Zortech, since _____.

【选项】the work performed by hourly wage workers at Zortech does not require a significantly higher level of skill than the work performed by hourly wage workers at Yorco does