In an attempt to improve the overall performance of clerical

Discussed in detail at the below mentioned link
in-an-attempt-to-improve-the-overall-performance-of-clerical-59719.html#p430654

In an attempt to improve the overall performance of clerical workers, many companies have introduced computerized performance monitoring and control systems (CPMCS) that record and report a worker’s computer-driven activities. However, at least one study has shown that such monitoring may not be having the desired effect. In the study, researchers asked monitored clerical workers and their supervisors how assessments of productivity affected supervisors’ ratings of workers’ performance. In contrast to unmonitored workers doing the same work, who without exception identified the most important element in their jobs as customer service, the monitored workers and their supervisors all responded that productivity was the critical factor in assigning ratings. This finding suggested that there should have been a strong correlation between a monitored worker’s productivity and the overall rating the worker received. However, measures of the relationship between overall rating and individual elements of performance clearly supported the conclusion that supervisors gave considerable weight to criteria such as attendance, accuracy, and indications of customer satisfaction.
It is possible that productivity may be a “hygiene factor,” that is, if it is too low, it will hurt the overall rating. But the evidence suggests that beyond the point at which productivity becomes “good enough,” higher productivity per se is unlikely to improve a rating.

Which of the following, if true, would most clearly have supported the conclusion referred to in lines 19-21?
(A) Ratings of productivity correlated highly with ratings of both accuracy and attendance.
(B) Electronic monitoring greatly increased productivity.
(C) Most supervisors based overall ratings of performance on measures of productivity alone.
(D) Overall ratings of performance correlated more highly with measures of productivity than the researchers expected.
(E) Overall ratings of performance correlated more highly with measures of accuracy than with measures of productivity.