Sparky Corporation uses the weighted-average method of process costing. The following information is available for February in its Molding Department: Units: Beginning Inventory: 37,000 units, 100% complete as to materials and 60% complete as to conversion. Units started and completed: 134,000. Units completed and transferred out: 171,000. Ending Inventory: 36,000 units, 100% complete as to materials and 35% complete as to conversion. Costs: Costs in beginning Work in Process - Direct Materials: $55,000. Costs in beginning Work in Process - Conversion: $60,850. Costs incurred in February - Direct Materials: $369,560. Costs incurred in February - Conversion: $611,150. Calculate the cost per equivalent unit of conversion.

a. 3.20

b. 4.98

c. 4.58

d. 3.91

e. 3.66