问题如下：
The
most appropriate response to Knight’s question regarding the potential future
scenario for the Heydon Quant Fund is:
选项：
A.only
the returns-based approach.
only
the holdings-based approach.
both
the returns-based approach and the holdings-based approach.
解释：
C is correct. Because the Heydon Quant Fund
would be changing its factor model by adding a new factor, the correlations of
the fund’s returns with the factors would likely change and the returns-based style
would change. Even though the investment universe is unchanged, the portfolio
holdings would likely change and the holdings-based style classification would
also will be affected.
这个return based, holding based, 能否具体讲解一下
