Use the following information for questions 5 and 6. The following information was available from the inventory records of Rich Company for January: Units Unit Cost Total Cost Balance at January 1 3,000 $9.77 $29,310 Purchases: January 6 2,000 10.30 20,600 January 26 2,700 10.71 28,917 Sales: January 7 (2,500) January 31 (3,700) Balance at January 31 1,500 5. Assuming that Rich does not maintain perpetual inventory records, what should be the inventory at January 31, using the weighted-average inventory method, rounded to the nearest dollar? a. $15,757. b. $15,356. c. $15,390. d. $15,540.