Marcel Co. uses the weighted-average cost method to account for inventory. Sales were $30,000 for the year. The number of units available for sale during the year was 180. The weighted-average cost of the goods available for sale was $20 each. The number of units left in ending inventory for the year was 50. How much was Cost of Goods Sold for the year?

a. $1,000

b. $2,600

c. $11,500

d. $3,600