Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

When underwriting new corporate bonds, matrix pricing is used to get an estimate of the:
Option A:required yield spread over the benchmark rate.
Option B:market discount rate of other comparable corporate bonds.
Option C:yield-to-maturity on a government bond having a similar time-to-maturity.

Answer: A