怎么理解三个选项

问题如下：

Q. Which of the following best explains why it is unlikely a poor-performing hedge fund would be added to an index?

选项：

A.Survivorship bias

B.Backfill bias

C.Selection bias

解释：

C is correct. Selection bias refers to when the benchmark inclusion criteria cover only those funds that have good performance and hence report their performance to attract new investors. A is incorrect; survivorship bias is when the benchmark stops including funds that have ceased operations, most likely due to poor performance, and hence does not fully represent the hedge fund universe. B is incorrect; backfill bias occurs when an index retroactively includes the performance of a fund before it is added to the index.