问题如下图：
选项：
A. 
B. 
C. 
D. 
解释：
我觉得这道题没有解释好～有没有周全的分析啊
品职答疑小助手雍 · 2019年11月05日
同学你好，这题主要是问为什么要用ASFR，因为在衡量信用风险时存在一个问题，银行的债务人非常多，而他们之间也会有相关性，随着人数的增加，要考虑的相关性呈几何级数增加，从而给信用风险计量造成很大困难。因此，采用ASRF模型时，银行会自行估计相关性，而使得在计量单个贷款时不用考虑它所在的贷款组合的影响。
pz-stepsutake · 2020年03月22日
上面解析，银行会自行估计相关性的说法对么？记得何老师讲P123例题时，相关性从来都不是银行自己确定的，而是根据监管机构的模型计算出来的啊
品职答疑小助手雍 · 2020年03月22日
这个相关性的确定不是唯一一种方法的，我在这问题下面在传个图片，是原版书里的话，红线部分有描述
NO.PZ2016072602000053 The Basel II risk weight function for the internratings-base(IRapproais baseon the asymptotic single risk factor (ASRF) mol, unr whithe system-wi risks thaffeall obligors are molewith only one systematic risk factor. The major reason for using the ASRF is: The mol shoulnot penon the granularity of the portfolio. The mol shoulportfolio invariant so ththe capitrequirefor any given lopen only on the risk of thloanes not penon the portfolio it is aeto. The mol shoulnot portfolio invariant anthe capitrequirefor any given loshoulnot penon the risk of other loans. The mol correspon to the one-yeVa 99.9% confinlevel. B is correct. Because the capitcharges for invicrets are aetogether, it must invariant to the rest of the portfolio. The mol also assumes infinite granularity. 老师，能麻烦讲一下b\c吗？
NO.PZ2016072602000053 The Basel II risk weight function for the internratings-base(IRapproais baseon the asymptotic single risk factor (ASRF) mol, unr whithe system-wi risks thaffeall obligors are molewith only one systematic risk factor. The major reason for using the ASRF is: The mol shoulnot penon the granularity of the portfolio. The mol shoulportfolio invariant so ththe capitrequirefor any given lopen only on the risk of thloanes not penon the portfolio it is aeto. The mol shoulnot portfolio invariant anthe capitrequirefor any given loshoulnot penon the risk of other loans. The mol correspon to the one-yeVa 99.9% confinlevel. B is correct. Because the capitcharges for invicrets are aetogether, it must invariant to the rest of the portfolio. The mol also assumes infinite granularity. 什么是错的
The mol shoulportfolio invariant so ththe capitrequirefor any given lopen only on the risk of thloanes not penon the portfolio it is aeto. The mol shoulnot portfolio invariant anthe capitrequirefor any given loshoulnot penon the risk of other loans. The mol correspon to the one-yeVa 99.9% confinlevel. B is correct. Because the capitcharges for invicrets are aetogether, it must invariant to the rest of the portfolio. The mol also assumes infinite granularity. 请问一下C，和B的区别
The Basel II risk weight function for the internratings-base(IRapproais baseon the asymptotic single risk factor (ASRF) mol, unr whithe system-wi risks thaffeall obligors are molewith only one systematic risk factor. The major reason for using the ASRF is: The mol shoulnot penon the granularity of the portfolio. The mol shoulportfolio invariant so ththe capitrequirefor any given lopen only on the risk of thloanes not penon the portfolio it is aeto. The mol shoulnot portfolio invariant anthe capitrequirefor any given loshoulnot penon the risk of other loans. The mol correspon to the one-yeVa 99.9% confinlevel. B is correct. Because the capitcharges for invicrets are aetogether, it must invariant to the rest of the portfolio. The mol also assumes infinite granularity. 请问，解析里，The mol also assumes infinite granularity.怎么理解
