A foundry produces circular utility access hatches $($manhole covers$).120$ covers are produced in a $10-$ hour shift, the productivity of the line is: Select one: $1200$ covers$/$hr$,$ O b$.12$ covers$/$hr$.$ c $120$ covers$/$hr$\backslash .1\mathrm{.}2$ covers$/$hr$.$ e $2$ covers$/$hr$\backslash$