The Dvorak keyboard requires less finger movement than the ubiquitous QWERTY keyboard. As a result, Dvorak keyboard users are not only able to type more words per minute, but are also less vulnerable to both repetitive stress disorder and carpal tunnel syndrome. Nonetheless, businesses, as well as consumers, have not adopted the Dvorak keyboard. Clearly, if the Dvorak keyboard is to become more widely used, its benefits must be more widely touted.
Which of the following, if true, casts the most doubt on the author`s conclusion?
【选项】The initial cost of manufacturing a Dvorak keyboard will be more expensive than that of a QWERTY keyboard.