再请教一题

GWD-8-Q34: GWD-13-28

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.

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

2. 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

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

4. sloth, found in Puerto Rico in 1991, have been dated at 34 million years old, making the sloth the earliest known mammal on
5. sloth which, found in Puerto Rico in 1991, was dated at 34 million years old, made the sloth the earliest known mammal of

C为正确答案

D为争议答案

我认为E才是正确的，请达人帮忙解释一下，谢谢啊。

我选D的爱

E不对，was错了，它是Fossils的谓语 应该用复数