What immediate effect will each of the following have on demand for car tires (under the assumption that other things equal)?

9,000 8,000 7,000 Marginal cost 6,000 5,000 Marginal cost and marginal revenue ($) 4,000 E 3,000 2,000 C 1,000 0 Marginal revenue -1,000 Quantity D 0 10 20 30 of cars, Q 40 50 60 70 80 60,000 40,000 Profit ($) 20,000 0 10 20 30 40 50 60 70 80 -20,000 Quantity of cars