[求助]请教费费34 (Test 2)

题目如下：

34. Conservationist: The population of a certain wildflower is so small that the species is headed for extinction. However, this wildflower can cross-pollinate with a closely related domesticated daisy, producing viable seeds. Such cross-pollination could result in a significant population of wildflower-daisy hybrids. The daisy should therefore be introduced into the wildflower’s range, since although the hybrid would differ markedly from the wildflower, hybridization is the only means of preventing total loss of the wildflower in its range.

Which one of the following is an assumption on which the conservationist’s reasoning depends?

A. The wildflower currently reproduces only by forming seeds.
B. The domesticated daisy was bred from wild plants that once grew in the wildflower’s range.
C. Increasing the population of the wildflower will also expand its range.
D. Wildflower-daisy hybrids will be able to reproduce.
E. The domesticated daisy will cross-pollinate with any daisy like plant.

宝典的解释：

思路：not+weaken。根据原命题成立则逆否命题成立的原理，把选项取非后，若能对文章产生削弱作用的，则为答案。
A. 与结论无关。另外也可以根据极端词only来进行排除。
B. 就算daisy不是in wildflower's range，wildflower-daisy hybrids也是in  wildflower's range。
C. 无关。
D. 把选项取非，变成：wildflower-daisy hybrids不能再繁殖。这样的话，总有一天，随着wildflower的消失，wildflower-daisy hybrids也会消失的，这样就不能达到prevent total loss of the wildflower in its range的目的了，从而也对结论进行了削弱。因此D为答案。
E. 无关。

我知道D是很清晰的答案，但想请教一下A为什么不对？

如果把A取非，Wildflower并非仅通过种子繁殖（如可扦插），那这种通过形成种子（viable seeds）的杂交手段，就不是惟一可以保护WF的方法了。对吗？