A company purchased supplies during the year totaling $21,000. At the end of the year, they made an adjusting entry to record $16,000 of supplies that had been used during the year. The ending balance in the Supplies account after the adjustment was $12,000. The beginning balance in the Supplies account was:

A. $5,000. B. $7,000. C. $9,000. D. $12,000