Hatello Company uses the weighted-average method in its process costing system. The Assembly Department started the month with 9,000 units in its beginning work-in-process inventory that were 70% complete with respect to conversion costs. During the month, an additional 90,000 units were transferred in from the prior department to begin processing in the Assembly Department. During the month, 87,000 units were completed in the Assembly Department and transferred to the next processing department. There were 12,000 units in the ending work-in-process inventory of the Assembly Department that were 20% complete with respect to conversion costs. What were the equivalent units of production for conversion costs in the Assembly Department for the month?

a) 93,000 units.

b) 83,100 units.

c) 87,000 units.

d) 89,400 units.