McGill Manufacturing Had 900 Units in Its Work in Process

McGill Manufacturing had 900 units in its work in process inventory at the beginning of a month. Of these units, 40 percent were complete with respect to labor, and 100% complete with respect to materials, and overhead. The firm transferred 4,000 units to the finished goods inventory during the month. It had 600 units of which 30 percent were complete and still in process at the end of the month. Equivalent production for the month was

A) 4,600 units.
B) 4,420 units.
C) 4,240 units.
D) 4,180 units. 4000 + (600 x 30%) .