Flagstone company uses a weighted-average process costing system. Company records disclosed that the firm completed 100,000 units during the month and had 20,000 units of work in process at month end which is 25% complete. Conversion costs related to the beginning work in process inventory amounted to $210,000, and amounts incurred during the current month totalled $840,000. If conversion is incurred uniformly throughout manufacturing, Flagstones equivalent-unit cost is:

A. $10.50

B. $10.00

C. $9.00

D. $8.40

E. $7.88