A producer is hiring 20 units of labor and 6 units of capital (bundle A). The price of labor is $10, the price of capital is $2, and at A, the marginal products of labor and capital are both equal to 20. Beginning at A, if the producer increases labor by one unit and decreases capital by 1 unit, then cost remains constant and output increases by 20 units. cost remains constant and output decreases by 20 units. output remains constant and cost increases by $8. output remains constant and cost decreases by $8. both cost and output remain constantl 9999's