Gaba Corporation uses the FIFO method in its process costing system. The Grinding Department started the month with $18,400$ units in its beginning work in process inventory that were $60\%$ complete with respect to conversion costs. An additional $74,000$ units were transferred in from the prior department during the month to begin processing in the Grinding Department. During the month $84,000$ units were completed in the Grinding Department and transferred to the next processing department. There were $8,400$ units in the ending work in process inventory of the Grinding Department that were $10\%$ complete with respect to conversion costs. What were the equivalent units of production for conversion costs in the Grinding Department for the month?

Group of answer choices

$84,000$

$64,000$

$84,840$

$73,800$