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?

Select one:

a$.$ It has decreased by $8\mathrm{.}3\%.$

b$.$ It has increased by $20\%.$

C$.$ It has decreased by $9\mathrm{.}1\%.$

d$.$ It has not changed.

e$.$ It has increased by $37\mathrm{.}5$ boxes$/$hr$.$