问题如下图：
选项：
A. 
B. 
C. 
解释请问考点在哪个知识点
A为什么不对
the holngs for the portfolio are not available. she wants the analysis to accurate possible. B is correct. Returns-baseattribution is typically usewhen the holngs ta are not available. Neither A nor C is correbecause returns-baseattribution is the least accurate of the three approaches. 放错位置了，现在放在了第一讲总述里了。
这个题目好像放错位置了
请问下课程里没有提业绩归因的方法呀？这个属于考点么？
业绩归因和portfolio turnover 有啥关系？
