(Table: Demand and Total Cost for Asgard) Use Table: Demand and Total Cost for Asgard. Valkyrie runs a natural monopoly that produces electricity for a small mountain village near Asgard. The table shows the demand facing Valkyrie and Valkyrie's total costs. The marginal cost of the fourth unit of output is: Table: Demand and Total Cost for Asgard Quantity (Megawatts) Price Per Megawatt Total Cost 1 $550 $1,000 2 500 1,075 3 450 1,200 4 400 1,375 5 350 1,600 6 300 1,875 7 250 2,200 8 200 2,575 Group of answer choices $125. $225. $175. $75