The inventory flows and related costs for a particular brand of basketballs sold by a sporting goods store during the month of October 2018 are noted below: Cost per Unit $8 $9 10/1/2018 10/2/2018 10/6/2018 10/11/2018 10/15/2018 10/21/2018 10/26/2018 10/30/2018 Beginning Inventory Purchase Sale Purchase Purchase Sale Purchase Sale # of Units 400 600 700 200 400 500 $12 $13 300 $16 100 If these basketballs sell to retailers for $20 each, what is this company's gross profit for October 2018 assuming that the company uses a periodic, FIFO inventory cost flow system? $26,000 $10,000 $12,300 $13,700 $16,000