15) A company purchased 90 units for $20 each on January 31. It purchased 180 units for $25 each on February 28. It sold 180 units for $60 each from March 1 through December 31. If the company uses the first-in, first-out inventory (FIFO) costing method, what is the amount of Cost of Goods Sold on the income statement for the year ending December 31? (Assume that the company uses a perpetual inventory system.) A) $1,800 B) $4,050 C) $4,500 D) $6,300