Choice "A" is correct. Many companies and agencies extinguish (or refund) long-term debt prior to maturity as a method of managing financial risk. In this case, the refunding is not considered an extraordinary event because it is not unusual and infrequent. The gain (retirement price less carrying amount of the old debt) will be included as part of continuing operations.
Choice "d" is incorrect. Gains or losses on early retirement of debt must be recognized at the time of the transaction.
Choice "b" is incorrect. The gain is not an extraordinary item, per the above discussion.
Choice "c" is incorrect. There is a gain on the refunding, not a loss, and the classification does not meet the extraordinary item criteria.