9.2-3. Consider the transportation problem having the following parameter table: Destination 1 2 3 4 10 5 Supply 2 Sorce 3 4(D) 8560 6 M 3 0 389 0 0 5180 7460 20 7 30 30 20 Demand 25 25 20 10 20 After several iterations of the transportation simplex method, a BF solution is obtained that has the following basic variables: x = 20, X21-25, x=5. X32=25, x345, xa2 =0, x430, X45 = 20. Con- tinue the transportation simplex method for two more iterations by hand. After these two iterations, state whether the solution is opti- mal and, if so, why.