Inventory Valuation Methods and Cost Flow Assumptions: A company uses the perpetual inventory system and employs the FIFO (first-in, first-out) and LIFO (last-in, first-out) inventory valuation methods. Analyze the impact of using different cost flow assumptions on inventory valuation, cost of goods sold (COGS), gross profit, and taxable income. Discuss the advantages and disadvantages of FIFO and LIFO methods in inventory management, financial reporting, and tax planning.