Data for a monopolist Quantity (Q) Price (P) Total Revenue (TR) Marginal Revenue (MR) Marginal Cost (MC) Average Total Cost (ATC) 14 $200 ? --- $190 15 $190 ? (A) $30 $179.33 16 $180 ? (B) $20 $169.38 17 $170 ? (C) $10 $160.00 18 $160 ? (D) $20 $152.22 Use the table above to answer the following question. Assume the table above describes a monopolist selling patented coolers. What is the MR of the 18th cooler sold (i.e. what should be the value in blank (B)