Sales during the year were 500 units. Beginning inventory was 250 units at a cost of $5 per unit. Purchase 1 was 400 units at $6 per unit. Purchase 2 was 200 units at $7 per unit. Ending inventory under the FIFO cost flow assumption (using a periodic inventory system) was: Select one: O a. $1,850. O b. $2,300. O C. $2,750. O d. $3,650