Brody Corp uses a process costing system. Beginning inventory for January consisted of 1,100 units that were 47% completed. 10,000 units were started into the process during January. On January 31, the inventory consisted of 550 units that were 79% completed. How many units were completed during the period?

a. 10,550

b. 9,450

c. 11,650

d. 11,100