The following information was collected for one of the costs at Demetra Manufacturing Corporation over the past two years: Units Produced total Cost This year 5000 $125,000 Last year 6000 $147,000 Assuming that there has been no change in the cost structure over the last two years and this activity is within the relevant range, this cost at Demetra would best be described as a: A. fixed cost B. mixed cost C. step-variable cost D. true variable cost