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:

                                                                                               Units
Beginning work in process inventory, May 1................16,000
Started in production during May................................100,000
Completed production during May................................92,000
Ending work in process inventory, May 31....................24,000

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 conversion costs.

Costs pertaining to the month of May are:

• Beginning inventory costs: materials, $54,560; direct labor, $20,320; and factory overhead, $15,240.

• Costs incurred during May: materials used, $468,000; direct labor, $182,880; and factory overhead, $391,160.

Using the first-in, first-out (FIFO) method, the equivalent units of production for conversion costs are:

a. 101,600 units.

b. 85,600 units.

c. 98,400 units.

d. 88,800 units.