Q10-5 A partial solution tree in applying branch and bound technique to assign 4 jobs to 4 persons such that the total cost is minimum, and each person is assigned with exactly one job, is shown below. Based on the nodes of this tree, what is the number of the node to explore in the next step? 0 start Lb= 4+3+1+2 = 10 2 3 4 A-3 A4 A Lb = 9+3+1+2 = 15 A2 Lb=5+4+2+2 -13 Lb=4+3+1+2 = 10 Lb=5+3+1+2 = 11 5 7 B- B-4 B-2 Lb= 4+3+3+2 =12 Lb=4+4+1+4=13 Lb = 4+6+1+2 = 13