问题如下：
Which of the following performance measures is most appropriate for an investor who is not fully diversified?
选项：
A.M-squared.
B.Treynor ratio.
C.Jensen’s alpha.
解释：
A is correct.
M-squared adjusts for risk using standard deviation (i.e., total risk).
这几个方法哪个是full diversified，哪个not full diversified总是记混。请问有没有好的记忆方法？
