GMAT Test Prep: CR-31061217 GMAT Critical Reasoning

Division Manager:I want to replace the Microton computers in my division with Vitech computers.General Manager:Why?Division Manager:It costs 28 percent less to train new staff on the Vitech.General Manager:But that is not a good enough reason.We can simply hire only people who already know how to use the Microton computer.

Which of the following, if true, most seriously undermines the general manager's objection to the replacement of Microton computers with Vitechs?
Select one of the following answer choices