31. Jack makes pies in a perfectly competitive market for baked goods. His cost schedule is reflected in the table below Quantity Total Cost $15 $21 $29 $39 Use marginal thinking to determine his production "optimum" if the price per pie in this competitive market is fixed and equal to $8/pie. a. He produces 0 units b. He produces 2 units c. He produces 4 units d. He produces 5 units e. Indeterminate