1. Consider the minimum cost flow problem shown below, where the bi values (net flows generated) are given by the nodes, the cij values (costs per unit flow) are given by the arcs, and the uij values (arc capacities) are given between nodes C and D. Do the following work manually? (a) Obtain an initial BF solution by solving the feasible spanning tree with basic arcs AB,CE,D E, and CA (a reverse arc), where one of the nonbasic arcs (CB) also is a reverse arc. Show the resulting network (including bi,cij, and uij ) in the same format as the above one (except use dashed lines to draw the nonbasic arcs and add the flows in parentheses next to the basic arcs. (b) Now consider the following BF solution. Starting from this BF solution, apply one iteration of the network simplex method. Identify the entering basic arc, the leaving basic arc, and the next BF solution, but do not proceed further