3. Division Manager：I want to replace the Microton computers in my division with Vitech computers.
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 I most seriously undermines the general manager's objection to the replacement of Microton computers with Vitechs?
(A) Currently all employees in the company are required t0 attend workshops on how to use Microton computers in new applications．
(B) Once employees learn how to use a computer, they tend to change employers more readily than before.
(C) Experienced users of Microton computers command much higher salaries than do prospective employees who have no experience in the use of computers．
(D) The average productivity of employees in the general manager's company is below the average productivity of the employees of its competitors．
(E) The high costs of replacement parts make Vitech computers more expensive to maintain than Microton computers．