The following expression models the total money earned by setting up a food stall at a funfair, where x represents the number of cheeseburgers sold. what does the constant term in the above expression represent? a. the constant -10 represents the cost of each cheeseburger at the food stall. b. the constant -10 represents the maximum number of cheeseburgers sold by the food stall at the funfair. c. the constant -10 represents the total money earned by setting up the food stall. d. the constant -10 represents the cost of setting up the food stall even if no cheeseburgers were sold.