What price should be charged to maximize societal benefit? A line graph with the price on the vertical axis and the quantity of watches sold per week on the horizontal axis. Three lines are shown. The marginal cost is a horizontal line at $100. Both the marginal revenue and the firm demand curve start at (1, $150). The marginal revenue line has a steeper negative slope than the firm demand curve. The marginal cost line intersects the marginal revenue curve at (3, $100), and intersects the firm demand curve at (5, $100). $75 $50 $150 $100