问题如下：
ABC is a French wealth management company. It invested $10 million in Corporation D’s 10-year senior unsecured bond. Being afraid that company D would default, ABC purchased a $10 million CDS on company D with a standardized coupon rate of 5%.
3 months later, company D files for bankruptcy, triggering various CDS contracts. ABC wealth company assesses the credit quality of the corporate bond they invested and the value of the CDS on the bond.
The following is the relevant information on Corporation D’s bonds currently trading in the market:
Bond 1: A 5-year senior unsecured bond trading at 40% of par.
Bond 2: A 10-year senior unsecured bond trading at 50% of par
Bond 3: A 6-year subordinated unsecured bond trading at 30% of par.
According to the information above, what is the cheapest-to-deliver obligation for a senior CDS contract?
选项：
A.30%
B.40%
C.50%
解释：
B is correct.
考点：CDS cheapest-to-deliver的理解
解析：
从Senior债券里面找Cheapest-to-deliver，Bond 1符合条件。注意，尽管Bond 3的价格更低，但是他是Subordinated，不在Senior CDS的保护范围里。
老师请问，Bond1，trading at 40% of par的意思是如果违约的话，债券交易价格是40%的面值。Bond2，trading at 50% of par的意思是如果违约的话，债券交易价格是50%的面值。
应该是指一旦违约，Bond 1赔付的是60%债券面值，Bond 2 赔付的是50%债券面值，对吧？而且40% par/50% par应该是不管是否违约都是以40%/50%面值进行交易
