求助！！老PREP 1-94的it指代问题

上岸喝水的鸭

这个问题happyself 有问过，可是没有解答，麻烦各位XDJM帮忙看看吧~

1-94
The decline of the mountain yellow-legged frog in the high reaches of the Sierra Nevada has

become severe enough for the United States Fish and Wildlife Service quite possibly to list it as an

endangered species in the near future.

(A) severe enough for the United States Fish and Wildlife Service quite possibly to list it

(B) severe enough so that the United States Fish and Wildlife Service could well list them

(C) severe enough for it quite possibly to be listed by the United States Fish and Wildlife Service

(D) so severe that the United States Fish and Wildlife Service could well list it

(E) so severe that they could well be listed by the United States Fish and Wildlife Service
答案D中的it，prep笔记的的解释是it指代mountain yellow-legged frog;
但是为什么不会产生指代decline的歧义呢？
如果是指decline的话，就好像不能说“ list it as anendangered species ”了吧~~~

上岸喝水的鸭

顶~~~~~······
麻烦知道的人指导一下吧~~~~~~~~~~

connie飘着

我也同问？有没有大牛回答一下  “ THE + N." 不是应该用复数的嘛？ 所以我以为 IT 是指 DECLINE 的

connie飘着

麻烦指点！！！