(a) A recipient may not use any employment test or other selection criterion that screens out or tends to screen out handicapped persons unless the test score or other selection criterion, as used by the recipient, is shown to be job-related for the position in question.

(b) A recipient shall select and administer tests concerning employment to best ensure that, when administered to an applicant or employee who has a handicap that impairs sensory, manual, or speaking skills, the test results accurately reflect the applicant's or employee's job skills, aptitude or other factors the test purports to measure except where those skills are the factors that the test purports to measure.