Department A had 4,700 units in work in process that were 72% completed as to labor and overhead at the beginning of the period; 29,000 units of direct materials were added during the period; 31,600 units were completed during the period; and 2,100 units were 25\% 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. 33,700 b. 31,600 C. 26,900 d. 29,000