In the solution of linear programming problems by Simplex method, for deciding the leaving variable
(a) The maximum negative coefficient in the objective function row is selected
(b) The minimum positive ratio of the right-hand side to the first decision variable is selected
(c) The maximum positive ratio of the right-hand side to the coefficients in the key column is selected
(d) The minimum positive ratio of the right hand side to the coefficient in the key column is selected