Adam Company uses the periodic inventory system. For May 2011, the beginning inventory consisted of 6,000 units that cost $12 each. During the month, the company made two purchases: 4,000 units at $13 each on May 15, and 2,000 units at $16 each on May 23. The ending inventory on May 31 was 4,000 units. Using the average-cost method, what is the amount of ending inventory for the month of May 2011?; Select one: O $98,000. $52,000. O $58,000 $104,000