$\backslash$table$[[$Problem IV$,,1,2,3,4],[,$A$,4,7,7,5],[,$B$,-1,1,2,2],[,$C$,2,2,3,2],[,$D$,0,3,4,5]]$

Questions $21$ through $25$ are based on Problem IV$.$

$(21)$ The total number of zero cells in Table $5$ is equal to:

$($a$)7$

$($b$)8$

$($c$)9$

$($d$)10$

$($e$)$ none of the above

$(22)$ The total cost of the optimal solution is:

$($a$)6$

$($b$)7$

$($c$)8$

$($d$)9$

$($e$)$ none of the above

$(23)$ The following assignment appears in an optimal solution:

$($a$)$ A$-1$

$($b$)$ A$-2$

$($c$)$ A$-3$

$($d$)$ A$-4$

$($e$)$ none of the above

$(24)$ The following assignment appears in an optimal solution.

$($a$)$ D$-1$

$($b$)$ D$-2$

$($c$)$ D$-3$

$($d$)$ D$-4$

$($e$)$ Not enough information to decide

$(25)$ This problem has two alternative optimal solutions.

$($a$)$ True

$($b$)$ False

$($c$)$ Not enough information to decide