4. MC.17-079.ALGO (Algorithmic) Department M had 2,000 units 51 % completed in process at the beginning of June, 13,400 units completed during June, and 1,000 units 28 % completed at the end of June. What was the number of equivalent units of production for conversion costs for June if the first-in, first-out method is used to cost inventories? a. 13,680 units b. 12,660 units c. 14,680 units d. 11,400 units