Most insomnia is not an illness or a physical condition so much as a symptom of another problem that may simply be a reaction to certain medications, anxiety about travel, or stress before a job interview.

1. an illness or a physical condition so much as a symptom of another problem that may simply be a reaction to certain medications
2. an illness or a physical condition so much as symptomatic of another problem that may be a simple one, like a reaction caused by certain medications
3. so much an illness or a physical condition but a symptom of another problem that may be as simple as when certain medications cause a reaction
4. so much an illness or a physical condition, but it is a symptom of another problem, maybe a simple one like certain medications causing a reaction
5. so much an illness or a physical condition but symptomatic of another problem, maybe simply a reaction to certain medications

答案是Ｅ，　我选Ｃ虽然觉得as when 也不对，但是觉得Ｅ中symptomatic　与an illness 　不平行

问一下，C、D、E使用了：not... but...结构，是不是改变了原句的意思？

原句中：not an illness or a physical condition so much as a symptom of another problem 

是说：大多数的失眠，不是一种疾病，也不是一种physical condition， 更不至于是其他什么问题的预兆。

改成not but 结构以后：not so much an illness or a physical condition but a symptom of another problem

是说：大多数的失眠，不是一种疾病，也不是一种physical condition，而是其他什么问题的预兆。

这样的话，是不是可以选A呢？

I choose A, but the answer is E..... very confused.

Is the answer key accurate?

要有主次之分。最主要是意思对，然后整体通顺，然后再是部分。C整句不通，细节部分就没什么好说的了。