Eley Company produces a single product. The cost of producing and selling a single unit of this product at the company's normal activity level of 40,000 units per month is as follows:Direct materials $42.60 Direct labour8.10Variable manufacturing overhead 1.10 Fixed manufacturing overhead 17.30Variable selling \& administrative expense1.80Fixed selling \& administrative expense8.00 The normal selling price of the product is $86.10 per unit. An order has been received from an overseas customer for 2,000 units to be delivered this month at a special discounted price. This order would have no effect on the company's normal sales and would not change the total amount of the company's fixed costs. The variable selling and administrative expense would be $1.20 less per unit on this order than on normal sales. Direct labour is a variable cost in this company. Suppose the company is already operating at capacity when the special order is received from the overseas customer. What would be the opportunity cost of each unit delivered to the overseas customer? a. $9.70 b. $7.20 c. $8.40 d. $32.50