A company purchased 100 units for $30 each on January 31. It purchased 100 units for $230 on February 28, It sold a total of 150 units for $100 each from March 1 through December 31. If the company uses the last-in, first-out (LIFO) inventory costing method, calculate the amount of ending inventory on December 31. (Assume the company uses a perpetual inventory system)

A. 1,500

B. 50

C. 1,000

D. 3,500