Strait Co. manufactures office furniture. During the most productive month of the year, 3,300 desks were manufactured at a total cost of $84,800. In the month of lowest production, the company made 1,160 desks at a cost of $64,800. Using the high-low method of cost estimation, total fixed costs are

a.$84,800 b.$53,945 c.$64,800 d.$20,000