Department G had $3,600$ units, $40\%$ completed at the beginning of the period, $12,000$ units were completed during the period, $2,000$ units were $20\%$ completed at the end of the period, and the following manufacturing costs were debited to the departmental work in process account during the period:Work in process, beginning of periodCosts added during period:Direct materials $(10,400$ at $$9\mathrm{.}8365)$Direct laborFactory overhead$ $60,000102,30079,80025,200$Assuming that all direct materials are placed in process at the beginning of production and that the first$-$in$,$ first$-$out method of inventory costing is used, the equivalent units for materials and conversion costs, respectively, areO a$.10,400$ and $10,960$O b$.14,000$ and $12,160$O c$.10,400$ and $10,240$O d$.14,000$ and $13,600$