Department A had 4,700 units in work in process that were 62% completed as to labor and overhead at the beginning of the period, 36,700 units of direct materlals were added during the period, 39,200 units were completed during the period; and 2,200 units were 37% 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. 34.500 b. 39,200 c. 41,400 d. 36,700