need help with this question please

Kimbeth Manufacturing uses a process cost system to manufacture Dust Density Sensors for the mining industry. The following information pertains to operations for the month of May 2012: The beginning inventory was 60% complete for materials and 20% complete for conversion costs. The ending inventory was 90% complete for materials and 40% complete for corversion costs. Costs pertaining to the month of May are as follows: The beginning inventory costs are: materials, $54,560; direct labor, $20,320; and factory overhead, $15,240. Costs incurred during May are: materials used, $468,000; direct labor, $182,880; and factory overhead, $391,160. Using the FIFO method, the equivalent unit cost of materials for May is $4.50$4.80$4.12$4.60