Serie Inc. reported the following results from last year's operations: Sales 16,800,000 Variable expenses 10,640,000 Contribution margin 6,160,000 Fixed expenses 5,488,000 Net operating income 672,000 Average operating assets 7,000,000 At the beginning of this year, the company has a $2,100,000 investment opportunity with the following characteristics: Sales $ 2,520,000 Contribution margin ratio 50% of sales Fixed expenses $ 1,108,800 Last year's margin was closest to: O 9.6% O 4.0% O 67.3% 36.7%