请教一道GWD题

Q33:

When an active tooth in the shark’s jaws is lost or worn down, many spare teeth lie in seemingly limitless reserve, each of which are ready to slide into the appropriate position.

1. When an active tooth in the shark’s jaws is lost or worn down, many spare teeth lie in seemingly limitless reserve, each of which are ready to slide into the appropriate position.
2. Whenever an active tooth is lost or worn down, many spare teeth lie in seemingly limitless reserve in the shark’s jaws, which are each ready to slide into the appropriate position.
3. Many spare teeth lie in seemingly limitless reserve in the shark’s jaws, each one of which are ready to slide into the appropriate position when an active tooth is lost or worn down.
4. The many spare teeth lying in seemingly limitless reserve in the shark’s jaws, each one of which is ready to slide into the appropriate position whenever an active tooth is lost or worn down.
5. In the shark’s jaws, many spare teeth lie in seemingly limitless reserve, each one ready to slide into the appropriate position whenever an active tooth is lost or worn down.

答案是A, 为何不选E？

我觉得是Ｂ呢

A　When an active tooth in the shark’s jaws is lost or worn down, many spare teeth lie in seemingly limitless reserve, each of which are ready to slide into the appropriate position.

should use "is"

E  In the shark’s jaws, many spare teeth lie in seemingly limitless reserve, each one ready to slide into the appropriate position whenever an active tooth is lost or worn down.

each,one重复, ready to前少了be动词

ＮＮ们指教

谢谢wawa的回答。A主谓不一致是硬伤，看来答案错了。

E中，我感觉ready前不需要be动词。each one的重复是相对错，不能排除。

B中，whenever意思感觉不对，which...修饰对象不清，可能修饰jaws.

仔细一看，Ｂ从意思上确实错了

E中,one指代前面的teeth，也就是each teeth的意思吧

所以each one ready to应该是可以的,独立主格