14 335 Brick and Vine is one of several bookstores for a university. An income statement for Brick and most recently completed period is as follows: Sales revenue $1.000.000 Cost of goods sold $660.000 Gross margin $340,000 Selling expense $100.000 Administrative expense $110.000 Operating income $130,000 On average, a book sells for $50. Variable selling expenses are $3.00 per book and the remaining selling expenses weet 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 Brick and Vine when the cost driver. X.equals the number of books sold? Oy - $105.000 - $5X Oy - 5205,000+ 5.5OX Y-$110,000 - $5X y-$100,000+ $5.50X None of the above