Hi, i would like some help regarding the question below:

We want to assign 4 people to 4 jobs so that the total cost of the assignment is as small as possible. The constraint to the problem is that each job is assigned to only one person, and each person is assigned with only one job. The table gives the cost of a person completing a particular job. Job 2 4 Person A 19 5 4 5 B 4 3 5 16 C 3 1 3 2 D 2 4 2 16 Using branch-and-bound algorithm based on setting lower bounds by row, find an assignment (one only) of the four jobs to the 4 people such that the total cost of the assignment is optimal. You must number the node according to the order that you draw the state-space tree.The assignment problem: 58 1, the lower bound cost is 11 + 14 + 13 + 22 = 60 (choose according to the lowest cost for each unassigned task without considering the constraints - each agent performs exactly one task).The assignment problem: 58 g C 5 73 Second alternative: assign agent a to job 2., calculate lower bound as follows: a>1 QWh=73 Lb =11+14+13+22=6o Ei)'2. Lb =12+11+13+22=58 start Lb =u+12+13+22=58 If a :> 2, the lower bound cost is 12. + 11 + 13 + 22 = 58 The assignment problem: 58 new Ub = 64 Lb =11+14+13+22=60 b - 1 8 2 Lb =12+14+19+23=68 c->1, d->4 O a-> 2 6 Lb =12+13+11+28=64 b -> 3 start Lb =12+11+13+22=58 9 Lb =11+12+13+22=58 3 Lb =12+13+11+23=59 c->4, d ->1 X > new Ub a ->3 Lb =12+13+23+17=65 = 64 Lb =18+11+14+22=65 b-> 4 4 X Lb =12+22+11+19=64 Ub = 64 > new Ub=64 a-> 4 1 2 3 4 Lb =40+11+14+13=78 X > initial Ub a 11 12 18 40 b 14 15 13 22 . If c => 1 and d => 4 , the lower bound cost is 12 + 13 + 23 + 17 = 65. C 11 17 19 23 17 14 20 28 . We eliminate this new branch as Lb > Ub