Average and marginal cost (AC and MC) $320 0 Average cost (AC) -Marginal cost (MC) $200.00 $180. 00 $160 00 $140 00 $120 0D $100 00 590.00 560.00 $40.00 $20.00 50.DO 2 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Output quantity (q) The graph shows the AC (blue line) and MC (red line) for a firm. If the price is $40, and the firm chooses to operate, firm profits are: O Negative O Zero O Positive