An income statement for Sam's Bookstore for the first quarter of the year is presented below: Sam's Bookstore Income Statement For Quarter Ended March 31 Sales $ 840,000 cost of goods sold 520,000 Gross margin 320,000 Selling and administrative expenses Selling $ 111,000 Administrative 126,000 237,000 Net operating income $ 83,000 On average, a book sells for $70. Variable selling expenses are $5 per book with the remaining selling expenses being fixed. The variable administrative expenses are 4% of sales with the remainder being fixed, The contribution margin for Sam's Bookstore for the first quarter is: Multiple Choice $613,600 $613,600 O $260,000 $746,400 $226,400