问题如下：
A firm has generated surplus cash through operating and redeems bonds before maturity. Which of the following equation is most accurate to calculate the gain or loss?
选项：
A.Gain or loss = carrying value - amortized historical cost of the bonds.
B.Gain or loss= carrying amount - required amount about the bonds redemption.
C.Gain or loss= carrying value - face value of the bonds.
解释：
B is correct.
The gain or loss is equal to the bonds' carrying amount minus the cash amount required to redeem the bonds.
carrying amount 和carrying value是否是同一个意思？
