Use this information about Department S to answer the question that follow. Department S had no work in process at the beginning of the period. It added 10,200 units of direct materials during the period at a cost of $61,200. During the period, 7,700 units were completed, and 2,500 units were 40% 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 $53,940, and factory overhead was $17,400. The total cost of units completed during the period was Oa. $131,208 Ob. $93,940 Oc. $46,200 Od. $109,340