TTGWD23-31一直的困惑

Q31:

According to some botanists, invasive plants are the second most serious threat, after habitat loss, to native species of plants and animals and to the maintenance of biologically diverse ecosystems.

1. threat, after habitat loss, to native species of plants and animals and to the maintenance of biologically diverse ecosystems

2. threat, after habitat loss, to native species of plants and animals and for maintaining biologically diverse ecosystems

3. threat, after losing their habitat, to native species of plants and animals and also to maintenance of biologically diverse ecosystems

4. threat to native species of plants and animals and for maintaining biologically diverse ecosystems, after habitat loss

5. threat to native species of plants and animals as well as to maintaining biologically diverse ecosystems, after losing their habitat

答案B, 品感觉,请问与D相比

after habitat loss的位置的不同会带来什么不同呢?

答案不是A吗? 

支持A.

threat to A and to B.

c为什么不对啊

c 的their 的指代不明。

支持A，句子结构为...are the...threat, ... , to...and to ...

满足该平行结构的只有A,C 但是C的also故意复杂化，应该删去

不过楼主MM已经考完GMAT了，呵呵