问题如下：
The manager selection process begins by defining the universe of feasible managers. When defining this manager universe, the selection process should avoid:
选项：
A.excluding managers based on historical risk-adjusted returns.
identifying the benchmark against which managers will be evaluated.
using third-party categorizations of managers to find those that might fill the desired role in the portfolio.
解释：
A is correct.
The focus of the initial screening process is on building a universe of managers that could potentially satisfy the identified portfolio need and should not focus on historical performance. Identifying a benchmark is a key component of defining the manager’s role in the portfolio, and third-party categorizations are an efficient way to build an initial universe which can then be further refined.
老师你好，
1、答案说是要避免基于历史的表现，但A说的是避免不包含历史表现，所以A是应该接受的不是应该避免的吧。哪里理解的不对吗
2、为什么不能基于历史的表现呢
