Mutijima Construction uses a weighted$-$average process$-$costing system. Materials are added at the beginning of production while conversion cost are incurred uniformly throughout manufacturing. Consider the data that follow. Units Beginning work in process $26,200$ Started in August $64,800$ Production completed $58,900$ Ending work in process, $40\%$ complete $32,100.$Conversion cost in the beginning work$-$in$-$process inventory totaled $$131,000,$ and August conversion cost totaled $$357,000.$ Assuming use of the weighted$-$average method, which of the following choices correctly depicts the number of equivalent units for conversion cost and the conversion cost per equivalent unit? $($a$)$ Equivalent Units for materials; $58,900$ and Conversion cost per Equivalent unit: $$5\mathrm{.}71($b$)$ Equivalent units for materials: $71,470$ and Conversion cost per equivalent unit: $$5\mathrm{.}68,($c$)$equivalent units for materials; $71,470$ and Conversion costs per equivalent units: $$6\mathrm{.}80,($d$)$ Equivalent units for materials: $91,000$ and conversion costs per equivalent units: $$5\mathrm{.}68,($e$)$ Equivalent units for materials: $91,000$ and Conversion costs per equivalent units: $$6\mathrm{.}80$