关于which不能指代整个句子的疑问

以下句子，C选项是对的

但据说在GMAT中which不能指代整个句子

怎么解释呢？C选项中which指代前面的内容吧

A. There are no legal limits, as there are for cod and haddock, on the size of
monkfish that can be caught, a circumstance that contributes to their depletion
through overfishing.
B. There are no legal limits on the size of monkfish that can be caught, unlike cod or
haddock, a circumstance that contributes to depleting them because they are being
overfished.
C. There are legal limits on the size of cod and haddock that can be caught, but not
for monkfish, which contributes to its depletion through overfishing.
D. Unlike cod and haddock, there are no legal size limits on catching monkfish,
which contributes to its depletion by being overfished.
E. Unlike catching cod and haddock, there are no legal size limits on catching
monkfish, contributing to their depletion because they are overfished.
Answer:

顶一下，哪位帮帮啊~

此题的答案是A。 （但是有争议，有人选C）

我认为C是错误的：正如你说，which 不能指代前面的句子，而只能修饰最近的名词；而如果修饰monkfish，句意不通。而只有A是正确的。fish是单复数相同的。