A company purchased 100 units for $30 each on January 31. It purchased 150 units for $25 on February 28. It sold a total of 150 units for $50 each from March 1 through December 31. If the company uses the weighted minus average inventory costing method, calculate the amount of ending inventory on December 31. (Assume that the company uses a perpetual inventory system.)
A. $2,700
B. $6,750
C. $4,350
D. $2,900