问题如下：
Which of the following statements regarding agency ratings is wrong?
选项：
A.Credit ratings will not change over time.
B.Rating agencies are not infalliable, they may make some mistakes.
C.Credit rating changes may lag behind the market's price changes.
解释：
A is correct.
Credit ratings can be very dynamic, the bondholders should not suppose that the issuer’s credit rating will remain the same through the entire holding period. B and C are also the credit rating’s risks.
老师 第一个选项也是对的吧？因为虽然credit rating是dynamic的 但是也不是随便变化的，所以不是change over time啊？
