问题
单项选择题
Which of the following is a general problem associated with external credit enhancements External credit enhancements:（）
A. only provide protection against systematic risk, not against idiosyncratic risk.
B. are very long-term agreements and are therefore relatively expensive.
C. are subject to the credit risk of the third-party guarantor.
答案
参考答案：C
解析：
According to the "weak link" philosophy adopted by rating agencies, the credit quality of an issue can not be higher than the credit rating of the third-party guarantor. Along these lines, if the guarantor is downgraded, the issue itself could be subject to downgrade even if the structure is performing as expected.
