Give a explanation please

5. Use the following to answer questions a, b, c, and d (25 points). Fit Planet began January with merchandise inventory of 110 crates of vitamins a cost of $75 per unit. During the month, Fit Planet purchased and sold merchandise on account as follows and uses a perpetual inventory systems: Requirements: a. Calculate available units and costs (5 points). b. If this company uses the FIFO inventory valuation method, what would be the cost of goods sold, cost of its ending inventory, and gross profit at January 31 (5 points)