请教关于限制性从句问题OG11和OG12的不同解释

舟楫

OG12-10Carnivorous mammals can endure what would otherwise be lethal levels of body heat because they have a heat-exchange network “which kept” the brain from getting too hot.

(A) which kept
(B) that keeps
(C) which has kept
(D) that has been keeping
(E) having kept

答案是B
OG11解释
The two underlined words contain two separate errors. The pronoun (which) introduces ***nonrestrictive*** clauses, which include information relevant but not critical to an understanding of the sentence.  The pronoun (that) introduces a restrictive clause, which is critical to understanding the sentence because the clause defines its antecedent.  Here, the clause following (which) defines heat-exchange network, so (that) must be used in place of (which).
而OG12 解释：In (A) and (C), which introduces a restrictive clause. Some writers follow the convention that which can only be used for nonrestrictive clauses, but insistence on this rule is controversial, and both (A) and (C) can be rejected on other grounds.
是不是可以认为GMAC不再将区分限制性从句和非限制性从句的引导词作为考点了呢？

jasonhaha

我觉得最严重的问题是时态。。。。。WHICH 和 THAT 在这里都OK。。。

舟楫

Thanks!!!

lilydenris

恩今天也看到这句话了 觉得OG12的解释也太含糊了吧 是不是代表以后which也可以引导限定性定语从句了啊？
but insistence on this rule is controversial...无语了...

Winnniee

做OG16的小伙伴看到这题依旧懵逼...