I have the correct answer but do not know how to work the problem.

24) The following information is provided by Arrow Company WIP Inventory, January 1 0 units Indinq 3,000 3.000 x 0 4 nits started Units completed and transferred out WIP Inventory, December 31 Direct materials $15,500 $18,400 irect Manufacturing Overhead The units in ending WIP Inventory were 80% complete for materials and 40% complete for conversion costs. At the end of the year, what are the equivalent units for conversion costs labor A) 2,800 B) 4,000 C) 1,200