$8.$ The table below gives a solution to transportation problem.

Warehouses

Plants I II III IV Suppl

y

A $121(10)410$

B $3(20)321(5)25$

C $4(5)2(10)5(5)920$

Demand $251015555$

$($a$)$ Is the solution feasible?

$($b$)$ Is the solution degenerate?$($c$)$ Is the solution optimum?

$($d$)$ Does the problem have alternate optimum solution? If yes, show at least one.