Power Co. purchased inventory as follows: November 2 300 units at $16 November 4 400 units at $20 November 8 200 units at $19 On November 7, Power Co. sold 500 units for $30 each. The average unit cost to be used for the cost of goods sold on November 7, in a perpetual inventory system, is OA) $18.44 B) $18 OC) $20 OD) $18.29