Brown Inc. uses the perpetual inventory system, and recorded the following data pertaining to raw material X during January 2020: Date Jan 1 Inventory Jan 11 Sold Jan 22 Purchase Units Received Unit Cost Units Sold Units on Hand $4.00 3,200 1,600 1,600 4,000 $4.70 5,600 The moving average unit cost of raw material X inventory at January 31, 2020 is O a $4.73 Ob. $4.62 O c $4.50 O d. 54.46