问题如下：
The relationship of correlation risk to credit risk is an important area of concern for risk managers. Which of the following statements regarding default probabilities and default correlations is incorrect?
选项：
A.Creditors benefit by diversifying exposure across industries to lower the default correlations of debtors.
B.The default term structure increases with time to maturity for most investment grade bonds.
C.The probability of default is higher in the long-term time horizon for noninvestment grade bonds.
D.Changes in the concentration ratio are directly related to changes in default correlations
解释：
The probability of default is higher in the immediate time horizon for non-investment grade bonds. The probability of default decreases over time if the company survives the near-term distressed situation.
为什么d不对呢 难道不是直接影响的吗
