Assume that we got the following Simplex Table while we were solving an LP model by the Simplex Algorithm. Basis X1 X2 X3 X6 RHS 7 X4 X5 X7 Max z 0 -6 0 0 -4 4 12 X5 2 0 -2 0 1 3 -1 24 X2 6 1 1 0 0 1 0 8 X4 -2 0 3 1 -1 -3 30 Continue to search by the Simplex Algorithm and find the optimal solution. Which option is wrong according to the optimal solution? Select one: a.X5, X3 and X4 are the basic decision variables at the optimal solution. b.z = 60 at the optimal solution c.Objective row entry of X1 is 43 at the optimal Simplex Table. d.X4 = 6 at the optimal solution. e.X2 = 6 at the optimal solution