问题如下图：
选项：
A. 
B. 
C. 
解释：
抵押品价值上升 ，对lender不是更有利么？margin变大，更加能保护么？为什么反而会decrease?
NO.PZ2018062020000009 Repo margin is the fferenbetween the book value of the security usecollateranthe value of the loan. If the market value of collaterincreases, the repo margin will give a margin of safety to the cash lenr. A is correct. Repo margin is negotiatebilaterally between counterparties. B is incorrect. Repo margin is the fferenbetween the market value of the security usecollateranthe value of the loan, not the book value. C is incorrect. The repo margin provis a margin of safety to the cash lenr if the collateral’s market value clines.之前做过一个题，选的就是b，为什么这个题b又不对了呢
NO.PZ2018062020000009 b和c分別錯哪了請解釋
请问老师c应该怎么理解？何老师说haircut可以理解为抵押品的市场价格和selling price之间打的折扣如果mkt value increase，这个margin应该变大对吧？那c不对，是因为mkt value虚高，导致lenr的折扣有水分所以不safe，这样理解对吗
老师你好，A和C要怎么理解呢，谢谢解答
