The Dulac Box plant produces 500 cypress packing boxes in two 10-hour shifts. Due to higher demand, they have decided to operate three 8-hour shifts instead. They are now able to produce 600 boxes per day. What has happened to productivity?
A) It has not changed.
B) It has increased by 37.5 boxes/hr.
C) It has increased by 20%.
D) It has decreased by 8.3%.
E) It has decreased by 9.1%.