A company just starting business made the following four inventory purchases in June: Number of units Date purchased Total cost June 1 160 units $380 June 10 180 units 590 June 15 180 units 660 June 28 170 units 520 $2150 A physical count of merchandise inventory on June 30 reveals that there are 290 units on hand. The inventory method which results in the highest gross profit for June is not determinable. the FIFO method. the weighted average unit cost method. O the LIFO method