Productivity among workers has greatly declined, with fewer projects

Productivity among workers has greatly declined, with fewer projects being completed. Because workers are increasingly assigned an unmanageable number of tasks, most work slower and accomplish less during the time they spend on the job. Therefore, an effective way for employers to increase productivity would be to minimize the number of tasks any individual worker is assigned at a given time, allowing her to focus on and complete a single project before moving on to the next one.
Which of the following, if true, would most support the recommendation above?

A. Programs that increase productivity have costs but they are nearly negligible for most large companies.

B. Most productive companies have already taken to minimizing the number of tasks their employees are assigned.

C. Enhancements to workplace amenities have been shown to increase productivity among workers.

D. Workers who perform poorly on many tasks are likely to perform poorly on fewer tasks, as well.

E. The productivity of workers with minimized task assignments is significantly higher, on average, than those assigned a higher number of tasks.