Can you solve this general accounting problem using accurate calculation methods?

FedEx Manufacturing had 6,200 units in work in process that were 50% completed as to labor and overhead at the beginning of the period. During the period, 37,800 units were completed and transferred out. At the end of the period, 3,000 units were started but not completedthey were 70% complete as to labor and overhead. 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 with respect to materials for the period was: a. 34,600 b. 35,900 c. 33,600 d. 31,800