Throughout this assignment G=(N,A) denotes the digraph depicted in the figure below: Let b=2130 and c=054321. 1. (2 points) Give the node-arc incidence matrix of G. 2. We consider the Mininum-Cost Flow Problem on G,b,c. a. (1 point) Give a tree solution that is not a feasible tree solution. b. (1 point) Show that the tree with arc-set T={e2,e3,e6} determines a feasible tree solution. c. (6 points) Solve the Minimum-Cost Flow Problem by applying the network simplex method starting at the the feasible tree solution in part b. Whenever there is a choice for the entering or leaving arc, choose the one with the smallest index