NO.PZ202201050100001301
问题如下：
The core-plus fixed-income composite includes a portfolio managed on behalf of the Bida Academy endowment fund. The trustees of Bida inform Bamako in writing that because of a change in investment policy, the endowment fund is no longer permitted to hold below-investment- grade securities. Bamako determines that henceforth, the Bida portfolio should be included in the core fixed-income composite rather than the core-plus fixed-income composite. The historical record of the portfolio must be:
选项：
A.
included in both composites.
B.
kept in the core-plus fixed-income composite.
C.
excluded from the core-plus fixed-income composite.
解释：
B is correct.
The portfolio’s historical performance must remain with the original composite. Portfolios must not be switched from one composite to another unless either documented changes to a portfolio’s investment mandate, objective, or strategy or the redefinition of the composite make it appropriate.
投资组合的历史表现必须与原始composite保持一致。 投资组合不得从一种composite转换为另一种composite，除非对组合的投资授权、目标或策略进行了记录在案的更改，或者composite的重新定义使其适当。
请教一下A选项为什么不对？
