Fuentes Industries uses a process costing system. For the month of December, the total equivalent units of production for conversion costs is 28,500 units. Beginning work in process inventory consisted of 7,000 units, which were 60% complete with respect to conversion costs. Ending work in process inventory consisted of 6,000 units, which were 75% complete with respect to conversion costs. How many units were started during the month of December?

-23,000 units

-24,000 units

-25,500 units

-27,600 units

-None of the above