所以是否可以得出结论，预防downside tail risk of the portfolio，首选就是排除掉G factor得分较低的公司？E&S在这个方面的优先级不如G高

问题如下：

Chang Ying runs an equity portfolio using ESG integration techniques which looks atE, S, and G independently. To reduce the downside tail risk of the portfolio whilst preserving the largest investable universe possible she could avoid:

选项：

A.All companies with low E scores. B.All companies with low S scores. C.Companies with exposure to coal fired power generation. D.Companies whose G score reflects insufficient financial oversight.

解释：

如果一家公司治理良好，他们也会以正确的长远思维处理环境和社会问题，从而避免或有效地管理重大风险，并抓住相关机会。相反，如果一家公司G方面的得分较低，反映了财务监管不足，如D选项，那么这家公司可能在E和S方面也会有欠缺。因此Chang Ying在整合ESG时，应该避免这一类公司。