Brick and Vine is one of several bookstores for a university. An income statement for Brick and Vine's most recently completed period is as follows: Sales revenue $1,000,000 Cost of goods solcl boon.000 Gross inargin $340,000 $100,000 $110,000 Selling expense Administrative expense Operating income $130,000 On average, a book sells for $50. Variable selling expenses are $3.00 per book and the remaining selling expenses are fixed. Variable administrative expenses are 5% of sales and the remaining administrative expenses are fixed What is the cost function for selling and administrative expenses at Rrick and Yine when the cost driver, X, equals the number of books sold? y = $105,000 + $5X y = $ 109,000 + $5.50X y = $110,000+ $5X y = $100,000 + $5.50x None of the above