Department A had 4,800 units in work in process that were 67% completed as to labor and overhead at the beginning of the period, 29,000 units of direct materials were added during the period, 31,100 units were completed during the period, and 2,700 units were 38% 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. 31,100 b. 29,000 c. 26,300 d. 33,800