March 1 Beginning Inventory 60 units at $10 March 5 Purchases 70 units at $12 March 10Sale 80 units sold at $15 on March 11 Sales Returns 20 units 50 units at $15 March 20 Purchase March 30 Sales 40 units sold at $20 Assuming that a periodic inventory system is used, what is the amount allocated to ending inventory on a FIFO basis? Select one: O a. $750 b. $840 c. $1,110 d $1.100