这两个都是什么方法啊

问题如下：

The CRO of an investment bank is considering which approach to use for aggregating risks across the bank’s trading and banking books. The CRO asks an analyst to provide a comparison between the compartmentalized approach and the unified approach. The analyst notes that the bank has extensive lending operations and trading operations in multiple countries, leading to large and diverse trading and banking books. Which of the following statements is correct regarding the compartmentalized approach or the unified approach?

选项：

A.One argument in support of the compartmentalized approach is that it gives a reasonable lower bound for economic capital. B.Estimating the capital required for various individual risk types using the compartmentalized approach allows the bank to account for any possible correlations between the risk types. C.Since each holding in the bank’s portfolio can easily be assigned to a specific risk type, the unified approach is typically the preferred approach to estimating economic capital. D.Using the unified approach may allow the bank to benefit from diversification effects that lead to lower capital requirements.

解释：

D is correct. If the holdings can be separated into different risk types, and the correlations between the risk categories are less than one, then this will lead to lower capital requirements for the bank. A is incorrect. The compartmentalized approach may give a prudent upper bound for economic capital. B is incorrect. The compartmentalized approach is a non-integrated approach in which the capital required for each risk type is estimated separately and then summed to find the capital required for the bank as a whole, without regard to any correlations or interactions. C is incorrect. The holdings in the bank’s portfolio are not easily assigned to a specific risk type, and if this were possible the compartmentalized approach may typically be preferred.