company just starting its business made the following four inventory purchases in June: Number of Total Date Units Cost Jun 1 150 $480 Jun 10 200 660 Jun 15 200 680 Jun 28 150 525 On June 25, the company made its first sale when a local customer purchased 500 units for $3,500. The company uses a perpetual inventory system. The inventory cost formula that results in the highest gross profit for June is O FIFO. O not determinable. O gross profit is the same under both cost formulas. O average.