[SC悬赏令] OG 关于代词指代前面介词里的词

Fossils of the arm of a sloth found in Puerto Rico in 1991, and dated at 34 million years old, made it the earliest known mammal of the Greater Antilles Islands.

(A)  sloth found in Puerto Rico in 1991, and dated at 34 million years old, made it the earliest known mammal of

(B)  sloth, that they found in Puerto Rico in 1991, has been dated at 34 million years old, thus making it the earliest mammal known on

(C)  sloth that was found in Puerto Rico in 1991, was dated at 34 million years old, making this the earliest known mammal of

(D)  sloth, found in Puerto Rico in 1991, have been dated at 34 million years old, making the sloth the earliest known mammal on

(E)  sloth which, found in Puerto Rico in 1991, was dated at 34 million years old, made the sloth the earliest known mammal of

OG的答案是D, OG解释A中的"it"错是因为无指代, Because sloth is the object of a preposition and not the subject of the sentence, there is no reasonable antecedent for the pronoun it;

第二题是:

The eyes of the elephant seal adapt to darkness more quickly than any other animal yet tested, thus allowing it to hunt efficiently under the gloomy conditions at its feeding depth of between 300 and 700 meters.

(A)  The eyes of the elephant seal adapt to darkness more quickly than any other animal yet tested, thus allowing it

(B)  The eyes of the elephant seal adapt to darkness more quickly than does any other animal yet tested, allowing them

(C)  The eyes of the elephant seal adapt to darkness more quickly than do those of any other animal yet tested, allowing it

(D)  Because they adapt to darkness more quickly than any other animal yet tested, the eyes of the elephant seal allow it

(E)  Because the eyes of the elephant seal adapt to darkness more quickly than do those of any other animal yet tested, it allows them

OG答案是C; OG的解释是: thesingular pronoun it correctly agrees with itsantecedent (elephant seal ).

可是如果按照第一题的思路, 那么C的"it"并不是无法指代前面介词中的elephant seal吗?