Department R had 4,100 units in work in process that were 79% completed as to labor and overhead at the beginning of the period; 36,300 units of direct materials were added during the period; 37,500 units were completed during the period; and 2,900 units were 34% 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 conversion costs for the period was

a. 39,347

b. 37,500

c. 35,247

d. 44,500