问题如下:
How does ex ante tracking error differ from ex post tracking error?
选项:
A.Ex ante tracking error takes into account the behavior of options whereas ex post tracking error does not.
B.
Ex post tracking error uses a more accurate forecast of future markets than the forecast used for ex ante tracking error.
C.
Ex ante tracking error uses current portfolio holdings exposed to the variability of historical markets, whereas ex post tracking error measures the variability of historical portfolio holdings in historical markets.
解释:
老师,C选项是什么意思