You are given the following simplex tableau for a minimization problem:

State conditions on the unknowns $a_1,a_2,a_3,b$ and $c$ such that the following statements are

true

$($a$)$ The current solution is infeasible.

$($b$)$ The current solution is optimal.

$($c$)$ The current solution is degenerate.

$($d$)$ The current solution is optimal and there are multiple optimal solutions.

$($e$)$ The optimal value is unbounded.