The correct answer is A. Please explain and show why.

Jsco Company uses the weighted-average method in its process-costing system. In March, the company computed its first processing department's equivalent units of production for materials and conversion and it turned out that the costs per equivalent unit for materials and conversion for March were equal. Operating data for the department for March appear below for direct materials (DM) and conversion costs %of DM 50% %of cC 25% completion: completion: Costs Units Completed and transferred out 35.000 400 1.600 Ending WIP inventory Additional cost information is provided below: Beginning WIP inventory 2 800 DM S 7.620 S 9,700 S 11.000 S 8.360 Cost added during March 3 Compute the department's cost of equivalent unit for direct materials (DM) in March. $1.40 $2.10 $2.80 $4.20 Frod E. None of the above