The Refining Department of Sweet Sugar Inc. had 55,000 tons of sugar to account for in December. Of the 55,000 tons, 45,000 tons were completed and transferred to the Boiling Department, and the remaining 10,000 tons were 60% complete. The materials required for production are added at the beginning of the process. Conversion costs are added equally throughout the refining process. Calculate the total equivalent units of production for conversion costs.

A) 6,000 units

B) 45,000 units

C) 51,000 units

D) 55,000 units