问题如下：
For a bond issued at a premium, using the effective interest rate method, the:
选项：
A.carrying amount increases each year.
B.amortization of the premium increases each year.
C.premium is evenly amortized over the life of the bond
解释：
B is correct.
The amortization of the premium equals the interest payment minus the interest expense. The interest payment is constant and the interest expense decreases as the carrying amount decreases. As a result, the amortization of the premium increases each year.
像请问一下amortization of premium和amortized cost 的区别在哪里，这两个需要怎么理解
