问题如下：
When underwriting new corporate bonds, matrix pricing is used to get an estimate of the:
选项：
A. required yield spread over the benchmark rate.
B. market discount rate of other comparable corporate bonds.
C. yield-to-maturity on a government bond having a similar time-to-maturity.
解释：
A is correct.
Matrix pricing is used in underwriting new bonds to get an estimate of the required yield spread over the benchmark rate. The benchmark rate is typically the yield to-maturity on a government bond having the same, or close to the same, time-to-maturity. The spread is the difference between the yield-to-maturity on the new bond and the benchmark rate. The yield spread is the additional compensation required by investors for the difference in the credit risk, liquidity risk, and tax status of the bond relative to the government bond.
In matrix pricing, the market discount rates of comparable bonds and the yield-to-maturity on a government bond having a similar time-to-maturity are not estimated. Rather they are known and used to estimate the required yield spread of a new bond.
看了解释还是不太明白B错的点在哪里？怎么改才是对的？
