Consider the following simplex tableau that arises in the middle of solving a linear programming problem to maximize an objective function 2 = 7x1-x3-4x4+x52x6 in a feasible region with 1, 2, 3, 4, X5, X6 20: I = 4-2 - 3x4 - 4x6 x3 = 3+2x - x4 - 3x6 x5=8-2x1 +2x4+3x6 z = 5+ 3x-24 + 4x6 At this stage, the basic variables are 2, 3, 5 and the nonbasic variables are x, 4, X6. (a) List all four possible pivot moves, and give the entering and leaving variables for each. See the list of pivot rules (b) What is the next pivot move if we follow Bland's rule? (c) What is the next pivot move if we follow the largest increase rule? (d) What is the next pivot move if we follow the steepest edge rule?