A company purchased 100 units for $20 each on January 31. It purchased 100 units for $30 on February 28. It sold 150 units for $45 each from March 1 through December 31. If the company uses the average cost inventory costing method, what is the amount of Cost of goods sold on the December 31 income statement? A) $3,750 B) $6,750 C) $3,500 D) $4,000