
Answer:
Additional Paid-in Capital for $20,000.
Explanation:
The Journal is as follows:
Cash A/c       Dr. $120,000
To treasury stock            $100,000
To Additional paid in capital   $20,000
(To record the treasury stock and Additional paid in capital)
Workings:
Cash = 10,000 shares × $12
    = $120,000
Treasury stock = 10,000 shares × $10
             = $100,000
Additional paid in capital  = 10,000 shares × ($12 - $10)
                      = 10,000 shares × $2
                      = $20,000