The following information is taken from company A's books: Income statement for the year ended: 12.31.2019 12.31.2020 Sales revenue $1,000,000 $1,200,000 Cost of sales 700,000 720,000 Gross profit 300,000 480,000 Operating expenses 150,000 180,000 Operating income 150,000 300,000 Interest expense 30,000 60,000 Pre-tax income 120,000 240,000 Income tax expense 42,000 84,000 Net Income $ 78,000 $156,000 12.31.2018 12.31.2019 12.31.2020 50,000 160,000 50,000 260,000 480,000 740,000 100,000 250,000 60,000 410,000 500,000 910,000 130,000 270,000 65,000 465,000 550,000 1,015,000 Balance sheet as of: Assets: Cash Accounts receivable Inventory Total current assets Property, plant and equipment, net Total assets Liabilities and stockholders equity: Liabilities: Current liabilities: Accounts payable Unearned revenue Total current liabilities Long term debt Total Liabilities Stockholders equity: Common stock at par Additional paid in capital Retained earnings Treasury stock Total stockholders equity Total liabilities and stockholders equity 25,000 36,000 61,000 342,000 403,000 38,800 37,400 76,200 400,000 476,200 50,000 52,000 102,000 420,000 522,000 1,000 200,000 141,000 (5,000) 337,000 740,000 1,000 200,000 240,000 (7,200) 433,800 910,000 1,000 200,000 300,000 (8,000) 493,000 1,015,000 Company A's return on assets during 2020 changed as follows: Select one: O a. The profit margin significantly increased and the asset turnover remained relatively constant so the return on assets increased O b. The profit margin significantly decreased and the asset turnover significantly increased but the return on assets remained the same OC. The profit margin significantly increased and the asset turnover significantly decreased but the return on assets remained the same O d. Both the profit margin and the asset turnover significantly increased so the return on assets increased