Exhibit 7-16 Short-run cost curves for a competitive firmA graph depicts three distinct curves. Quantity of output (in units per hour) is on the horizontal axis from values 0 to 9 where the increment is 1. Cost per unit (in dollars) is on the vertical axis from 0 to 110 in increments in 10 units. The checkmark-shaped passes through (2,20), (4,30), (5,50), and (6,80). Average total cost (ATC) curve which is an upward-shaped parabola passes through (2,20), (4,30), (5,50), and (6,80). Average variable cost (AVC) curve passes through (4,30) and it is an upward-facing parabola. In Exhibit 7-16, the firm should shut down in the short run if the market price of its product falls below: a. $50 per unit. b. $80 per unit. c. $20 per unit. d. $30 per unit