Serie Incorporated reported the following results from last year's operations: Sales Variable expenses Contribution margin Fixed expenses Net operating income Average operating assets $ 16,800,000 10,640,000 6,160,000 5,488,000 $ 672,000 $ 7,000,000 At the beginning of this year, the company has a $2,100,000 investment opportunity with the following characteristics: Sales Contribution margin ratio $ 2,520,000 50% of sales Fixed expenses $ 1,108,800 Last year's margin was closest to: Multiple Choice 67.3% 9.6%