Strait Co. manufactures office furniture. During the most productive month of the year, 3,100 desks were manufactured at a total cost of $84,200. In the month of lowest production the company made 1,140 desks at a cost of $64,500. Using the high-low method of cost estimation, total fixed costs are

a.$19,700

b.$53,045

c.$64,500

d.$84,200