D选项是什么意思呀

NO.PZ2018122701000002 问题如下 A risk analyst is comparing the use of parametric annon-parametric approaches for calculating Vanis concerneabout some of the characteristipresent in the loss tWhiof the following stribution characteristiwoulmake parametric approaches the favored methoto use? Skewness in the stribution Ftails in the stribution Scarcity of high magnitu loss events Heteroskesticity in the stribution C is correct. 考点 ： non-parametric method 解析 ： Non-parametric approaches caccommote fat tails, skewness, anany other non-normfeatures thccause problems for parametric approaches. However, if the ta periothis usein estimation inclus few losses or losses with low magnitu, non-parametric metho will often prorisk measures thare too low. Henparametric metho woulbe more appropriate in those situations. 这个知识点掌握的不是很牢固，这道题还理解的不太透彻，想跟老师再学习一下参数法就是normal和lognormal两种，ABlognormal也是有偏或者肥尾啊？C是因为极端值少，所以用非参数法的优势就不大，但是如果参数法会不会更可能不合适啊？异方差就导致不能很好估计参数，所以不能选。谢谢老师

NO.PZ2018122701000002 Ftails in the stribution Scarcity of high magnitu loss events Heteroskesticity in the stribution C is correct. 考点 non-parametric metho解析 Non-parametric approaches caccommote ftails, skewness, anany other non-normfeatures thccause problems for parametric approaches. However, if the ta periothis usein estimation inclus few losses or losses with low magnitu, non-parametric metho will often prorisk measures thare too low. Henparametric metho woulmore appropriate in those situations. 尤其是后面however那段

NO.PZ2018122701000002

问一道题：NO.PZ2018122701000002