The table below shows output, marginal cost, and average variable cost for the production of pairs of shoes. All co Marginal Average Output Cost Variable Cost 50 60 140 70 45 115 90 35 95 110 30 80 130 35 65 150 60 60 170 105 65 190 180 75 210 230 90 230 290 110 TABLE 7-6 126)Refer to Table 7-6. The firm's marginal product of its variable factor is maximized when it26) produces units of output. A) 50 B) 90 C) 100 D) 110 E) 170