Cotton Corporation uses a process$-$cost accounting system. The company adds direct materials at the start of its production process, while conversion cost occurs evenly throughout manufacturing. Cotton has no beginning work$-$in$-$process inventory; its ending work in process is $90\%$ complete. Which of the following sets of percentages would be used to calculate the correct number of equivalent units in the ending work$-$in$-$process inventory?

Multiple Choice

Materials, $90\%$; conversion cost, $90\%$

Materials, $90\%$; conversion cost, $100\%$

Materials, $100\%$; conversion cost, $100\%$

Materials, $100\%$; conversion cost, $90\%$

Materials, $100\%$; conversion cost, $10\%$