Department S had no work in process at the beginning of the period. It added 12,600 units of direct materials during the period at a cost of $88,200; 9,450 units were completed during the period; and 3,150 units were 22% completed as to labor and overhead at the end of the period. All materials are added at the beginning of the process. Direct labor was $57,400 and factory overhead was $9,000. The total conversion costs for the period were a. $48,400 b. $66,400 c. $57,400 O d. $9,000