A firm had 600 units in process inventory at the beginning of a month. Of these units, 30% were complete with respect to labor, materials, and overhead during the month. It had 500 units of which 40% were complete and still in process at the end of the month. Equivalent production for the month was:
a)5,680 units
b)5,380 units
c)5,200 units
d)5,180 units