问题如下：
Which of the following is most likely to be used when selecting securities based on Dynamo’s credit strategy approach?
选项：
A.Macro factors
B.Expected excess returns
C.Average option-adjusted spread
解释：
B is correct.
Analyzing expected excess returns against the expected magnitude of the credit-related risks is key to the bottom-up approach. Once the credit universe has been divided into sectors, the investor identifies the bonds with the best relative value within each sector. If Dynamo decides that two issuers have similar credit-related risks, then it will typically compare credit spread measures and buy the bonds of the issuer with the higher spread because those bonds likely have a higher potential for excess returns. For issuers with different credit-related risk, Dynamo must decide whether the additional spread adequately compensates for the additional credit risk.
bottom up 从个体security到宏观层面啊，为什么不选A？
