8. Consider a manufacturing firm which uses natural gas to generate its own electricity. The electricity is used to run its manufacturing equipment. If the price of natural gas rises this would lead to A. a shift up in the average fixed cost and average total cost curves B. a shift up in the marginal cost, average total cost, and average fixed cost curves C. a shift up in the marginal cost, average variable cost, and average fixed cost curves D. a shift up in the marginal cost, average variable cost and average total cost curves 9. Which one of the following statements is FALSE? 150 100 Cost (RM) 50 10 15 Output (units) A. The vertical gap between curves B and C is equal to average variable cost. B. Average fixed cost decreases with output. C. The vertical gap between curves B and C is equal to average fixed cost. D. Curve B comes closer to curve C as output increases because of a decrease in average fixed costs. 10. The long run is a period of time in which A. economic efficiency is achieved B. the firm is able to maximize total profit C. the quantities of all inputs can be varied D. the firm can hire all the workers that it wants to employ, but it does not have sufficient time to buy more equipment