Consider the incomplete branch-and-bound tree below obtained when solving the following maximization problem. Max 4x1+5x2 Subject to X1+4x2 S 10 3X1-4x2 S6 X1,x220 X1, X2: int Z*= 23.5 (x1, x2) = (4 , 1.5) X2 2 2 X251 Z 18 7* = 18.3 (x:", xz')=(2, 2) (X1", x2") = (3.3, 1) ? ? a) Complete the branch-and-bound tree by identifying the variable to branch on next, the corresponding branching constraints, and the LP relaxation solution at each node. (10 points) b) Identify whether each leaf node in the branch-and-bound tree can be fathomed or not. Justify your answer. (3 points) c) Use the branch-and-bound tree information to find the optimal solution to the integer program. (2 points)