(Use this information to answer questions 18 to 22): A company produces two products made from aluminum and copper. The table below gives the unit require ments, the unit production man-hours required, the unit profit and the availability of the resources (in tons). Aluminum Copper Man-Hours Unit Profit Product 11 0 2 50 Product 21 1 3 60 Available 10 6 24 19. (5 points) Within what range for the profit on product 2 will the optimal production solution in question 18 remain optimal? (a) (45,70) (b) (50,75) (c) (50,70) (d) (45,75) 20. (5 points) What is the total profit when the profit associated with product 2 is increased to 70? (a) 540 (b) 520 (c) 560 (d) 580