A packaging factory runs a five$-$station serial production line $($A$-$B$-$C$-$D$-$E$).$ The following table shows the process times in minutes $($or minutes$/$unit$,$ i$.$e$.,$ the time to process one unit$)$ of the five stations.

$\backslash$table$[[$Station$,$Process Time $($minutes$/$unit$)],[$A$,9],[$B$,10],[$C$,7],[$D$,12],[$E$,4]]$

What is the process time of the system?

$12$

$7$

$10$

$42$