Department A had 4,400 units in work in process that were 78% completed as to labor and overhead at the beginning of the period; 27,900 units of direct materials were added during the period; 29,700 units were completed during the period; and 2,600 units were 26% 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 Oa 32,300 Ob 25,300 Oc 27,900 Od. 29,700