Marlborough Corporation has provided the following for three months of income statements. Sales in Units Less. cost of goods sold Operating expenses Advertising Depreciation expanse Total operating expenses January February 3,000 300.000 120.000 180.000- 210.000 3.500 350.000 $5,000 149500|| 60507 March 400.000 160.000 240,000|| 10.000 25.000 22000 15.000 Classify each of the company's expenses as variable, fixed durised