What is the equivalent units of production for Refining in the Work-in-Process (WIP) inventory, considering the beginning inventory of 17,500 units at 10 percent completion, transferred-in costs from Mixing, and current work of 55,300 units with respect to Refining costs?

A) 55,830 units
B) 72,500 units
C) 57,830 units
D) 58,830 units