Department S had no work in process at the beginning of the period. It added 13,200 units of direct materials during the period at a cost of $79,200. During the period, 9,900 units were completed, and 3,300 units were 35% 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 $64,119, and factory overhead was $19,899.

The total cost of units completed during the period was

a.$116,820 b.$59,400 c.$161,568 d.$134,640