Answer:
The credit on December 31 is to credit Treasury Stock with $15,000.
Explanation:
There are two methods for accounting for Treasury Stock. The first is the par value method. With this method, the Treasury Stock account is debited or credited with the par value for each transaction, while the difference in par value is taken to the Additional Paid-in Capital account.
Using the cost method, the Treasury Stock account is debited and credited with the value of each transaction and the Additional Paid-in Capital account is not affected.
This implies that under the cost method, the purchase and resale of treasury stock is recorded by debiting and crediting the treasury stock account by the actual cost of purchase and actual value of sale.