这题不是很理解，请解释说明下

NO.PZ2022120703000089 问题如下 Whiof the following ESG strategies is least likely useprivate equity firms? A.Positive screening B.Thematic investing C.Negative screening C is correbecause \"like other investor types, private equity investors mcertainly impose exclusionary screening i.e. negative screening on any number of criteria to restriinvestment in certain sectors, either normatively or ethically fine However, private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteriHowever, portfolio managers cbenchmark segments of the portfolio against smaller investment universes, even inclung public companies, if ta comparability exists. Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter\"; anleast likely ththey wouluse negative screening.A is incorrebecause \"private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteria … Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter.\"B is incorrebecause \"private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteria … Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter.\" 感觉A和C的非常牵强。A为什么“并不妨碍”，可以举例子吗？C排除性筛选时，为什么一定要用指数和基数，排除性筛选的时候，本身就很大程度上是基于道德或信仰。对于某公司或行业，虽然缺少信息披露，但是就是直接排除呀。否则，那不就是反向的积极筛选。请举例子。

NO.PZ2022120703000089问题如下 Whiof the following ESG strategies is least likely useprivate equity firms? A.Positive screeningB.Thematic investingC.Negative screening C is correbecause \"like other investor types, private equity investors mcertainly impose exclusionary screening i.e. negative screening on any number of criteria to restriinvestment in certain sectors, either normatively or ethically fine However, private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteriHowever, portfolio managers cbenchmark segments of the portfolio against smaller investment universes, even inclung public companies, if ta comparability exists. Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter\"; anleast likely ththey wouluse negative screening.A is incorrebecause \"private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteria … Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter.\"B is incorrebecause \"private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteria … Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter.\" 另外，怎么区分positive screening和negative的呢？

NO.PZ2022120703000089问题如下 Whiof the following ESG strategies is least likely useprivate equity firms? A.Positive screeningB.Thematic investingC.Negative screening C is correbecause \"like other investor types, private equity investors mcertainly impose exclusionary screening i.e. negative screening on any number of criteria to restriinvestment in certain sectors, either normatively or ethically fine However, private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteriHowever, portfolio managers cbenchmark segments of the portfolio against smaller investment universes, even inclung public companies, if ta comparability exists. Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter\"; anleast likely ththey wouluse negative screening.A is incorrebecause \"private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteria … Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter.\"B is incorrebecause \"private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteria … Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter.\" 本题为什么不能选A？未上市股票公司为什么不能用负面筛选投资策略？

NO.PZ2022120703000089 问题如下 Whiof the following ESG strategies is least likely useprivate equity firms? A.Positive screening B.Thematic investing C.Negative screening C is correbecause \"like other investor types, private equity investors mcertainly impose exclusionary screening i.e. negative screening on any number of criteria to restriinvestment in certain sectors, either normatively or ethically fine However, private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteriHowever, portfolio managers cbenchmark segments of the portfolio against smaller investment universes, even inclung public companies, if ta comparability exists. Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter\"; anleast likely ththey wouluse negative screening.A is incorrebecause \"private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteria … Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter.\"B is incorrebecause \"private equity investors not have the benefit of the breah anversity of inces anbenchmarks of the listeequities space, limiting opportunities for peer comparability analysis or portfolio optimization efforts arounESG criteria … Hence, it is more likely ththe GPs mapply some form of positive screening or thematic focus within their respective investment charter.\" 私募投资者无法享受到上市股票领域指数和基准的广度和多样性带来的好处（可选的投资标的非常少），和负面筛选的相排斥性在哪里？这个逻辑可以帮忙梳理一下吗，感谢！