X Company uses a perpetual inventory system. The company's beginning inventory and its purchases during the month of December are presented in this table: Date Quantity Unit Cost/ Selling price Dec. 3 Beginning inventory 200 units $2 7 Purchase 500 3 13 Purchase 400 4 20 Sale 300 10 30 Sale 400 10 Refer to the above data: Assuming that the company uses the LIFO flow assumption, Gross Profit during December was: * $4,500 $5,100 $2,500 None of the above