Use this information about Department A to answer the question that follow. Department A had 4,600 units in Work in Process that were 63% completed as to labor and overhead at the beginning of the period. 30,900 units of direct materials were added during the period, 32,800 units were completed during the period, and 2,700 units were 27% completed as to labor and overhead at the end of the period. All materials are added at the beginning of the process. The first-in, first-out method is used to cost inventories. The number of equivalent units of production for material costs for the period was a. 28,200 b. 35,500 c. 30,900 d. 32,800