问题如下：
Wang, a junior credit strategist, made the following statements about the structured financial instruments.
Statement 1: Because the collateral for a CDO is usually corporate loans or bonds, CDOs do not provide much diversification benefit compared with corporate bonds, and they do not offer unique exposure to a sector or market factor.
Statement 2: Because of this dual protection for creditors, covered bonds usually carry lower credit risks and offer lower yields
Statement 3: The correlation of expected defaults on the collateral of a CDO affects the relative value between the senior and subordinated tranches of the CDO.
选项：
A.Statement 1 is correct and statement 2 is wrong
B.Statement 2 is correct and statement 3 is wrong
C.Statement 1 is correct and statement 3 is correct.
解释：
答案：C is correct
解析：Strucured financial instruments的概念考查
解析：三个Statement都正确，为原版书原句。考试对这部分的要求是了解即可。
statement1中， they do not offer unique exposure to a sector or market factor.怎么理解？
