问题如下：
Which of the following statements describing a par curve is incorrect?
选项：
A. A par curve is obtained from a spot curve.
B. All bonds on a par curve are assumed to have different credit risk.
C. A par curve is a sequence of yields-to-maturity such that each bond is priced at par value.
解释：
B is correct.
All bonds on a par curve are assumed to have similar, not different, credit risk. Par curves are obtained from spot curves and all bonds used to derive the par curve are assumed to have the same credit risk, as well as the same periodicity, currency, liquidity, tax status, and annual yields. A par curve is a sequence of yields-to-maturity such that each bond is priced at par value.
C不对吗？没明白C为什么不对