老师可以解释一下这道题么

问题如下：

If a portfolio includes different asset classes, which of the following statements about ESG integration is most accurate?

选项：

A.The manager will be using a discretionary approach to portfolio construction. B.ESG integration is marked by a high degree of variation depending on asset class. C.The asset classes will be limited to public equity, fixed income, and infrastructure.

解释：

B is correct. ESG integration is marked by a high degree of variation by asset class, which means there can be a wide range of diverse approaches (strategies) within and between asset classes in the same portfolio. Although the level of ESG integration available varies by asset class, it is available in more asset classes than just listed equities, fixed income, and infrastructure. ESG integration can be accomplished using either a discretionary or systematic investment strategy.