A department adds materials to a process at the beginning of the process and incurs conversion costs uniformly throughout the process. For the month of January, there were no units in the beginning work in process inventory: 87000 units were started into production in January; and there were 20000 units that were 50% complete in the ending work in process inventory at the end of January. What were the equivalent units of production for materials for the month of January? 77000 equivalent units 67000 equivalent units O 87000 equivalent units O 97000 equivalent units